Sericulture in the Cévennes: from a first visit, autumn 2010

Simon Charsley

Simon Charsley

Prof.Simon Charsley’s name evokes mixed feelings of respect, admiration and affection in our minds. Of course, he belongs to the older generation, the classical phase of Indian sericulture and in every sense is a classicist. Marked by its characteristic all pervading ‘enthusiasm’ (to borrow Charsley’s own word), the classical phase has left a large legacy, of which the succeeding ‘techno-savvy’ age was little solicitous. Charsley was born in 1939 in England while the Second World War was looming large. He studied Philosophy and Social Anthropology at Cambridge. After obtaining PhD from the University of Manchester in 1968, Charsley started teaching Social Anthropology at the University of Glasgow, where he still continues to teach at the age of seventy one. He has held positions at Makerere College, Uganda (1965-6), University of Manchester (1967-8), Department of Sociology, University of Glasgow (1968-85) etc. Prof. Charsley had a key role in the preparation of ‘Beneficiary Assessment’ (BA) for the World Bank’s National Sericulture Project and was the Principal Adviser for BA to the CSB. Professor Charsley calls himself an expert on South Indian Sericulture and is proud of donning that label.

Professor Charsley spent his prime years in India, and took up study on a topic which would have appeared rather unfashionable to the contemporary intelligentsia. His introduction to Indian Sericulture was quite accidental. In his own words”... I first came to India on a Younger Scientist exchange programme and found sericulture in Mysore. The enthusiasm that I met led me to a research project on the silk industry and how it worked in practice, and also to many good friends....” That was in the mid seventies- an era marked by rapid modernisation of Indian sericulture sector. The result of his intensive study of the rural livelihood was the classic “Culture and Sericulture (1982)” which still remains one of the most authentic documentations on Indian sericulture and probably the only one comparable to the work of Lefroy and Ansorge (1915), though different in perspective and purpose. Subsequently he wrote a number of papers practically covering every aspect of the industry viz.regulated markets, middlemen, technology, silk reeling etc. which still remain most valuble reference material for students of respective disciplines.

Indian sericulture is indebted to Prof. Charsley, primarily for bringing it into the contemporary developmental rhetoric. He was the first and (unfortunately) the last to address sericulture as a livestock industry. Probably its scope of being so designated is largely under-estimated by the academics and policy makers. Prof. Charsley argued that sericulture shares much with and historically has led the way for other livestock industries and advocated its importance in the developmental context. His view of sericulture- as a ‘study material’ in social and anthropological assessment of development in a society where people are separated not only by status, culture and life circumstances but also by religion caste and politics is still highly relevant.
It is high time that the International Sericultural Commission considered prof. Charsley for its prestigios Louis Pasteur award. In this article Professor Charsley writes on the remnants of sericulture and silk industry in Cévennes, in southern France. The article shows how well the sericultural past is preserved in the French psyche, that they use it as a tourist bait. Shouldn’t we take a cue from this?

The Cévennes, in southern France, is an attractive area for summer tourists who want something other than sea and beaches. It is part of the Massif Central, the mountainous centre at France’s heart, with a high and wild National Park and, to its east and south, an area of wiggling wooded river valleys with precipitous rocky sides. These enclose small towns and villages with handsome old limestone houses often clinging to the steep slopes. It is a country of striking views and opportunities for enjoying ‘the great outdoors’. It is also one in which economic decline left, set in the marvellous landscapes, a supply of old houses in need of renovation. Over the last 30 years or so it has attracted numerous British and other northern Europeans to buy such houses, renovate them, construct swimming pools and settle in for at least a major part of the year. It is also a region with a distinctive history, much of it of peasantfarming, poverty, conflict and disasters. The disasters have arisen over the centuries from depopulating disease, political and religious warfare, extremes of torrential flooding, destructive frosts and, for these and other reasons, repeated collapse of livelihoods. However, its history has also included the memory of a golden age of prosperity, based in sericulture. There is evidence for its beginning here as early as the twelfth century but its conspicuous flourishing is considered to date only from the early eighteenth century. Though serious retreats as well as advances followed, it climaxed in 1853 after advancing during the first half of the nineteenth century. Then, struck by epidemics of silkworm disease, particularly pebrine before any effective means of controlling it was known, and by imports of cheap silk from Italy and the Far East, it ran down to virtual extinction over the following hundred years. After the Second World War, before it had entirely disappeared, efforts to give it a kiss of life were made with government support but no success.



A promotional poster: Saint-Hippolyte museum



The most recent effort at revival began to be seriously considered in the 1970s. In 1972 a school teacher in the village of Monoblet, by name Michel Costa, set about reviving knowledge of silkworm rearing as an instructive and engaging activity for his primary school pupils (Laurens 2004: 145). Perhaps he had been stimulated himself by a special edition of a school newspaper, Le Petit Cévenol, from 1930. It had been written, illustrated and printed by six girl pupils aged 9 to 12 years and was centred on their participation at home in the silkworm rearing which was still going on in their villages at the time (Cévennes 1997: 3-19). In 1977 a new Mayor of Monoblet came in with a project for ‘soil to silk garment’ production, and Michel Costa, his deputy as mayor, founded an Association for the Development of Sericulture in the Cévennes (ADS) to encourage and support rearing. By 1981 there had been sufficient progress for a co-operative of rearers and weavers to be formed with government support. It set up business in a former filature. About the same time, factories were started, also by ADS at Monoblet and by another organisation at Le Vigan, a larger town 30 kms to the west. They were to reel, prepare raw silk for weaving and to weave it. A further enterprise of ADS was a Silk Museum first at Monoblet and then moved to another former silk centre, Saint-Hippolyte, where a silk-garment workshop and a boutique for selling silk products were also established. As a later observer notes (Laurens 2004: 145), a mutually supporting network of linked enterprises of rearing and manufacturing and marketing and displaying was filling out.



          Mountages displayed at the Saint-Hippolyte museum

About this time a British entomologist and biologist, Dr John Feltwell, who settled and restored an old magnanerie or rearing house, also became involved. In 1983 he reported on ‘The revival of the silk industry in Basse-Cévennes’ in the Proceedings of the British Entomological and Natural History Society. The revival, he said, was ‘not necessarily run by Cevenol people in the heart of the Cévennes’: they remembered ‘all too well the great labour and energy expended in the magnanerie and are not likely to return to it lightly’ (1983: 24). But there was also sericultural progress to excite potential rearers and enthusiasts. A new mulberry significantly more productive and less demanding in land and in labour for leaf picking appeared. This was a legacy of government attempts from the 1950s to revive the industry then. New varieties from Japan had been sent in 1956 to an agricultural research centre near Alès, the old hub of the Cévennes silk industry. There a cultivar named Kokuso 21 had been identified as particularly promising for Cévennes conditions. It was still growing there 25 years later and in 1982 cuttings were made available for sale at the Monoblet museum (Feltwell 1983: 25).

From the beginning of this attempted revival there had also been a separate strand to thinking about it, or perhaps two such strands. Heritage or patrimoine as the French usually call it more pointedly, increasingly recognised as fulfilling a need for identity for the Cévennes and its people was one. In 1987 the Council of Europe [1] started sponsoring such heritage projects with its ‘Cultural Routes’ programme. Silk and Textile Routes were amongst the first projects to be selected for development, and funds for ‘Chemins de la Soie – European Silk Itineraries’ were provided (Clavairolle 1994). UNESCO also had a similar initiative at the global level [2], distinguished in France as ‘Routes de la Soie’, and Cévennes was a prime site for it. Heritage and identity were becoming an international industry in themselves.

A French filature: from St. Jeans Museum

The other and more directly material strand of thinking was an interest in securing a profitable place on the international tourist map. Remains of the sericultural past there were aplenty on the ground, but they did not have any such obvious appeal as sun, sea and the beach for northern European visitors. Things of potential interest needed to be given value, developed and pointed out if they were not to be missed by uninformed visitors. It was a more obvious asset to have sericulture being practised, though its seasonality in a temperate climate was a limitation: it would not be as readily available as tropical sericulture, but could at least be made to coincide with the main summer holiday season for visitors [3]. As well as live rearing providing additional points of attraction, they could be linked with sights to be discovered in countryside well worth exploring for its own sake, and with static displays in museums and elsewhere. The experience offered could thus be enriched and the potential returns increased. Promotion to the tourist industry through paper publications as well as television and then the internet took off. In recent times therefore, silk and its history have been promoted as a major focus around which other attractions in the Cévennes could be built up. It is visible as houses often standing high above terraces that were originally built on the steep and rocky hillsides with hard manual labour for the creation of mulberry plantations. An almost fanatical attention came to be aimed at charting the distinctive styles of silk-rearing architecture to be seen in the streets of villages and small towns, as well as large isolated houses set in what were once mulberry plantations. From the nineteenth century altogether different and even larger filature buildings also survive, built for capitalist ventures beside the rivers that provided their essential water supply. The last of these closed at Saint-Jean du Gard in 1965. One grand old filature was reopened in the early 1990s but by 1999 the project had been abandoned. Today the buildings are either converted to other purposes or remain derelict, but their working days, together with other picturesque aspects of sericulture, are pictured in the museums alongside collections of the silks, equipment, machinery and the propaganda media of the industry. There and in the shops catering for the visitors, originals and reprints of the postcards which played an important part in publicising and glamorising sericulture, at the beginning of the twentieth century particularly, continue in the same exercise today [4].

   A renovated rearing house with a mulberry twig on the fore ground

Just what happened over the last two decades is not yet documented, but the revival of sericulture as industry and livelihood is over. Today, three museum displays remain and one restored magnanerie, somewhat out of the way in its location, opens in the two main tourist months of the year. The only rearing being carried on is on an occasional and minute scale in connection with the displays at these. Nevertheless there is a presence and the memory is alive.
From Alès however, once Alais, capital of the Cévennes and centre of the industry, the only remaining sign of the silk industry is a fine statue of Louis Pasteur, great pioneer of microbiology who, starting in 1865 carried out his research on pebrine, the most dangerous of silkworm diseases there [5].

Statue of Louis Pasteur at Alès with a
mulberry tree in the background

He unravelled the complex nature of the disease and the means that were soon to be known across the sericultural world, of controlling it by practices of cellular rearing and microscopic examination of the mother moths. In the twentieth century, the Alès State Sericultural Research Station was taken onto a world stage. Its director, André Schenk, in 1948 organised there the 7th International Sericultural Congress which was to re-launch the worldwide trading industry after the set-backs of the War period. Then in 1955 it held the first International Technical Sericultural Conference from which emerged the International Sericultural Commission of which Schenk was the first Secretary-General. Its history in silk was coming towards its end however. In 1978 the Alès Research Station itself closed, its activities and staff moving mainly to France’s great city of the silk trade, Lyons on the River Rhône in the east of the country. Pasteur, his statue identifying him as ‘saviour of sericulture’, still looks out on the town from his prominent position in front of Fort Vauban, the seventeenth century castle in the centre of the town now again flourishing, but in other ways. Its distinguished presence in sericultural history is over.

Prof Charsley can be contacted at Email: s.r.charsley@socsci.gla.ac.uk  

For more details and his work go to: http://www.gla.ac.uk/departments/sociology/staff/simoncharsley/  

To read Prof. Charsleys blog go to: http://www.simoncharsley.blogspot.com/

REFERENCES

Cévennes 53/4. 1997. Architectures et Paysages de la Soie: le Fil de la Mémoire. Florac: Parc National des Cévennes

Clavairolle, Françoise 1994. ‘L’éducation des vers à soie: savoirs, représentations, techniques’, L’Homme, 129, 34: 121-45

Feltwell, John 1983. ‘The revival of the silk industry in the Basses-Cévennes’, Proceedings of the British Entomological  and Natural History Society, 16: 24-29

Laurens, Lucette 2004. De l‘arbre d’or à la sériciculture: filière et gestion culturelle du territoire dans les Cévennes’,  in Charlery de la Masselière, Bernard (ed) Fruits des terroirs, fruits défendus: identités, mémoires et territoires, Toulouse:  Presse universitaire de Mirail

FOOT NOTES

1. The Council of Europe was established by the Treaty of London in 1949 with its seat in Strasbourg, France. It now has 47 member countries, compared with the 27 of the European Union, and many activities and organisations, including a Parliamentary Assembly and the European Council on Human Rights. See http://www.coe.int/ ; http://en.wikipedia.org/wiki/Council_of_Europe .

2. UNESCO: United Nations Educational, Scientific and Cultural Organization. ‘The Silk Road’, routes across the landmass west of China along which silk and other good traded from ancient times, was a paradigm for its Cultural Routes programme in 1994.

3. The rest of silk processing and manufacture, with the exception of weaving, are in practice likely to be more difficult to display accessibly and interestingly.

4. Cards and one of their main creators, the multi-talented Gabriel Lafont, are valuably displayed and discussed by Daniel Travier in Cévennes 53/4, 1997: 20-21.

5. Also for a time in 1869 at St Hippolyte du Fort.

OUT BREAK OF A NEW INVASIVE PEST, PAPAYA MEALYBUG "PARACOCCUS MARGINATUS" IN SOUTH INDIA - A SERIOUS THREAT TO SERICULTURE INDUSTRY




JB. Narendrakumar

 J.B.Narendra Kumar and M.A.Shekhar

Mr. J.B. Narendra Kumar, Scientist-C working with Central Sericulture Research and Training Institute, Mysore, India. An agriculture post-graduate, interested in the agriculture entomology. Mr Narendrakumar can be contacted at jbnarendra@gmail.com

Dr. M.A. Shekhar, Scientist-D is the Sectional Chief of Pest Management Laboratory, Central Sericulture Research and Training Institute, Mysore. Has developed many IPM packages for the control of mulberry and silkworm pests

INTRODUCTION

The papaya mealybug, Paracoccus marginatus (Hemiptera: Pseudococcidae) is native of Mexico and Central America and it was first noticed in the year 1992 (Williams and Granara de Willink, 1992). During the year 2006, this pest was first reported in Coimbatore area of Tamil Nadu on Papaya. Now it has become a major pest of mulberry spreading fast in sericulture districts of Tamil Nadu causing heavy loss to sericulture industry and has made an entry into bordering districts of Karnataka also, ie., Chamarajanagar and Mysore. As per a recent survey report, an area of about 2,500 acres of mulberry plantation in three districts of Tamil Nadu is severely infested with this invasive pest. Many mulberry gardens have been dried up due to severe infestation and considerable acreage of mulberry has been uprooted.

HOW TO DIFFERENTIATE PAPAYA MEALYBUG FROM TUKRA MEALYBUG?

When mealybugs are pressed in between two pieces of white paper, papaya mealy mealybug gives greenish yellow stain, whereas tukra mealybug gives a pinkish stain. Also, when papaya mealybugs are transferred into alcohol, the body colour turns to black within half an hour. Adult females of papaya mealybugs are yellowish with short waxy filaments around the margin and measure about 3 mm with short caudal filaments, body fluid is yellow in colour, and specimens in alcohol turn bluish black. The detailed biology of the pest is yet to be studied.

LIFE CYCLE

Each adult female mealybug lays about 400-500 eggs with an incubation period of 3 to 4 days depending up on the prevailing temperature. In females, there are 3 stages (ie., egg, nymph & adult) and in case of males, there are 5 stages of development (ie., egg, nymph, pre-pupa, pupa & adult). The first instar nymphs (crawlers) are very active, very small and occupy tender shoot portion or tender leaves and feed by sucking the sap. Later they settle at one place, and continuously suck the sap. Adult females live for 30 to 60 days whereas males do not feed and live for very short duration. They possess a pair of transparent wings. The females do reproduce parthenogentically. Adult females are yellow in colour covered by white waxy secretion and short waxy filaments around the body and short caudal filaments.

The pest feeds on the sap of the plants by inserting its stylets into the epidermis of the leaf and stem. In doing so, it injects a toxic substance into the plant system thus resulting in chlorosis, stunted growth of plants, deformation of leaves, early leaf drop, a heavy build up of honey dew secretion and finally death of plants. Normally insecticides are not much effective against mealybugs due to waxy covering over their body. Since the adult mealybugs are sedentary in nature, biological suppression of this pest by natural enemies is an ideal alternative and has less risk to non target organisms.

HOST RANGE

It has got a wide host range of over 60 species of plants including economically important ones such as Annona squamosa (Custard apple), Carica papaya (Papaya), Psidium guajava (Guava), Hibiscus rosa-sinensis (Shoe flower), Cajanus cajan (red gram), Ipomoea spp. (sweet potato), Manihot esculenta (Tapioca), Gossypium hirsutum (cotton), Jatropha curcus (Jatropha), Vigna ungiculata (Cow pea), Tectona grandis (Teak), Solanum melongena (brinjal), Lycopersicon esculentum (Tomato) and weed plants like Parthenium hysterophorus (parthenium) & Abutilon indicum (country mallow). Annona squamosa, Carica papaya, Manihot esculenta and Melongena (Meyerdirk and Kauffman, 2001). It is infesting many weeds like Parthenium, hedge plants belonging to Euphorbiaceae family. In Tamil Nadu it has even devastated Jatropa plants which were grown for bio diesel purpose.

DAMAGE SYMPTOMS IN MULBERRY

Heavy infestation of the Papaya mealy bug is noticed on the under surface of leaves and usually along the veins and midribs in older leaves and on all areas on the tender leaves. Severely affected older leaves turn yellow and dry up. Tender leaves become crinkled. Terminal shoots become bunched and distorted. Heavy mealybug populations produce a large volume of honeydew, which facilitate the development of black sooty mould, which covers the infectedportion. The mealybug injects a toxin as it feeds on leaves, which results in chlorosis (yellowing) stunting, deformation, early leaf fall. Development of sooty mould makes the mulberry leaves unfit for silkworm rearing. The Papaya mealy bug infests all parts of the mulberry plant unlike the pink mealy bug, Maconellicoccus hirsutus, which infests only the apical portion.

MANAGEMENT OF PAPAYA MEALYBUG

For the management papaya mealy bug infesting mulberry no studies have been carried out. To meet the immediate requirements of the industry a modified IPM was formulated on the line of IPM of pink mealy bug infesting mulberry. The same modified IPM was tested with in the severely infested mulberry gardens in Tamil Nadu (Erode and Coimbatore districts) where, nearly 1500 to 2000 acres of mulberry gardens were infested. The farmers are following the modified IPM package formulated and recommended together by CSR&TI, Mysore and Tamil Nadu Agriculture University, Coimbatore and are able to reduce the infestation to a considerable extent. Modified IPM package has given 70 - 80 percent reduction in pest infestation. The silkworm rearing brushing capacity which had come down drastically by 80 to 90% has increased and the leaf yield has also considerably improved.

To prevent the outbreak of the pest, authorities of the region should draw a comprehensive plan on war footing measures. The young crawlers of the pest are very minute and appear like fine powder to naked eye and they can be easily drifted to different places through wind. It is not possible to combat this pest only through chemical measures. Simultaneously, we should also employ physical and biological methods to reduce the incidence of this dreaded pest.

In North America this pest has been controlled to an extent of 90% through classical bio-control approach. CSRTI, Mysore in collaboration with NBAII (Formerly PDBC), Bangalore and Tamil Nadu Agricultural University, Coimbatore has initiated a research project to develop control measures on the lines developed in North America. NBAII has already made all proposals to import the exotic bio-control agents to test them in India to control this pest.

IPM PACKAGE FOR PAPAYA MEALY BUG, PARACOCCUS MARGINATUS

• Prune the entire mulberry garden and make in to one batch. (If 2 batches are maintained, the pest will migrate from one garden to adjoining garden. To avoid this prune the entire garden at one time).
• Collect the pruned shoots along with infested portions in polythene bags. Place these cut infested portions on burning fire.
• Immediately after pruning, spray 0.2 % DDVP (25ml in 10 lts water) over the pruned stumps and surrounding soil.
• Burn all dry branches, shoots present in and around mulberry field by taking it out of the plot.
• 2nd spray of 0.1% Roger 10 – 15 days after pruning (30ml in 10lts)
• 3rd spray of 0.2% DDVP 10 days after 2nd spray.
• 5 days after 3rd spray, release predatory lady bird beetles (Cryptolaemus montrouzieri or Scymnus coccivora) @ 250/500 beetles for 1 acre.

All the farmers have to practice the above control measures simultaneously.

 In addition, the same treatment of chemical insecticide spray should be given to near by Agriculture and Horticulture crops also.

 Efforts should be made to enmass spray of insecticides to all near by crops and adjoining fallow land, as the pest is polyphagous and it may shift to adjoining weeds also.

NOTE: As a prophylactic measure, all the farmers should compulsorily spray 0.2% D.D.V.P. to mulberry gardens of age 15 to 20 days after pruning in each crop. This will help in controlling other insect pests of mulberry too.

 In Sri Lanka & Hawaii islands, release of parasitoids alone has given control of papaya mealybug to the tune of 90-95%. These parasitoids have been already imported. Once they are released in the infested mulberry gardens, spraying of insecticides may be discontinued.

Recent Achievements in Selection and Breeding of the Silkworm Bombyx mori L in Bulgaria

P. Tzenov

Dr. PANOMIR IVANOV TZENOV was born in Vratza, Bulgaria in 1961. He took his MSc from The University of Zootechnics and Veterinary Medicine – Stara Zagora in Animal breeding engineering – sericulture. He obtained his PhD. in sericulture in 1996. Dr. Tzenov started his career as a technologist in silkworm egg production at the “Silkworm breeding and egg production enterprise”, Vratza, under the Sericulture Experiment Station (SES) Vratza. He became the head of the station in 1987. From 1994 to 2003 he served as The Director of SES, Vratza and as National Director of the project “Rehabilitation of sericulture”, financed by FAO during 2000 – 2002. Presently he holds the position of Executive director of Bulgarian National Center of Agricultural Sciences (NCAS), Sofia. He is member of various reputed national and international forums such as International Working Group on Sericulture Germplasm” under FAO, International Working group on the global silk handcraft cottage industries and silk enterprises development” under FAO, The Publishing council at the National Center of Agricultural Sciences, Bulgaria etc. He is the founder president of Black, Caspian Seas and Central Asia Silk Association (BACSA). He has contributed immensely to general sericulture, silkworm breeding, egg production, rearing technology and cocoon and silk processing. He has 164 published papers to his credit and holds author’s certificates for two commercial silkworm hybrids. Dr. Tzenov is the chairman of the advisory committee of CONCEPT: Council for Nature Conservation and Environmental Protection, India.
Dr. Tzenov can be contacted at: panomir@yahoo.com

ABSTRACT

A method for selection of silkworm breeds and hybrids, tolerant to adverse rearing conditions, based on a previous testing of silkworm breeds/hybrids and choose of the most tolerant was developed. Two new four-way hybrids, manifested the highest tolerance to adverse rearing conditions along with a satisfactory high productivity under optimal rearing were created. By using a polyvoltine strain in the breeding process two new silkworm breeds were created as parents of a F1 silkworm hybrid which is characterized with comparatively good productivity and simultaneously a higher tolerance to adverse rearing conditions. All the 3 new tolerant to adverse rearing conditions silkworm hybrids have been examined in the system of State agency for variety testing and recognized as original. Two new silkworm hybrids for higher silk yield were created. They manifested average fresh cocoon weight 2.674 g, silk shell weight 0.632 g, shell percentage 23.64 %, filament length 1347 m, raw silk percentage 42.00 %, fresh cocoon and raw silk yield by one box of eggs 43.88 kg and 7.57 kg respectively - a productivity, comparable with the best world standard. A method for selection of sex limited for larval markings silkworm breeds, characterized with higher tolerance to adverse rearing conditions was developed. By breeding of 4 new sex – limited for larval markings strains a higher egg production efficiency by means of higher cocoon yield and fecundity at the P1 egg category level was obtained and a F1 four – way hybrid, having high productivity, combined with a higher tolerance to adverse larval rearing conditions was created and approved by the government as original. A method for selection of sex limited for cocoon colour highly productive silkworm breeds was developed. Four new sex – limited for cocoon color silkworm F1 commercial hybrids which manifest a pupation rate and productivity, comparable with those of the control have been created.

Keywords: silkworm, Bombyx mori L., selection, breeding, Bulgaria

INTRODUCTION

The beginning of a purposive silkworm selection and breeding in Bulgaria was dated 114 years ago with the establishment in 1896 of the Sericulture Еxperiment Station (SAES) in Vratza. In the 30th - 40th years of the last century two main strains were maintained and reared at the field level in Bulgaria, namely Yellow local, with yellow cocoons and cream color of raw silk and White Baghdad, having white cocoons. The White Baghdad race is considered as the oldest at the Balkan peninsula and had been selected by the ordinary farmers for many years.
One of the main targets of Sericulture Experiment Station (SES) in Vratza since its establishment and during its more than one century old activity has been the improvement of silkworm races and hybrids in order to increase the cocoon and raw silk yield and their quality.

Up to the beginning of 30’s of 20th century the station had not maintained its own silkworm genetic resources, but tested periodically the strains imported from different countries (mainly France and Italy) before their introduction at the private egg producing companies.

In the 40’s the station introduced several yellow cocoon races like Askoli, Var, Abrucio and Almeria from France and Italy and using this material some local yellow cocoon lines were evolved.

During the period 1944 – 1952 hybrids between the Yellow local and Golden Chinese race had been tested in Bulgaria and introduced to the field. In order to improve the lines of the Yellow local race, European yellow cocoon breeds Askoli, Var and Alpen were imported during the period 1949-1950. In the end of this period white cocoon silkworm breeds and hybrids became more popular in the world due mainly to their better silk dyeing quality. From 1965 to 1970 many new silkworm lines have been selected in Bulgaria by segregation from Italian and Japanese white cocoon F1 hybrids.

In 1969 the government approved the first white cocoon Bulgarian F1 commercial hybrids.

After 1970 the silkworm breeding work in Bulgaria was expanded and many new breeds and hybrids had been created and introduced until nowadays.

Taking into account the very big importance of the genetic resources for a successful breeding work the number of breeds, maintained at SAES - Vratza and the Agricultural universities was increased from 20-25 at the beginning of 70’s to over 300 in 2010.

The research work in the field of silkworm genetics and breeding was directed to studies on the interactions between the genotype and environment, heterosis expression in F1, positive transgressions expression in F2, combining ability, heritability, correlations, regressions, inheritance of the main qualitative and quantitative characters, implementation of the intensive inbred-lines breeding, methods for creation of initial populations for silkworm breeding, breeding of sex-limited breeds, use of partheno and androgenesis in the silkworm breeding, breeding of silkworm lines and hybrids for summer-autumn rearing, and having higher tolerance to adverse rearing conditions etc..

In the recent years the silkworm breeding in Bulgaria was directed to three main aims: viz. Breeding strains and hybrids tolerant to adverse rearing conditions; Breeding strains and hybrids for higher silk yield and Breeding sex-limited for larval markings and cocoon color strains as parents of commercial F1 hybrids, tolerant to adverse rearing conditions and hybrids, with high cocoon and silk productivity.

Breeding strains and hybrids tolerant to adverse rearing conditions.

In this work we used two methods. They were 1. Method of breeding tolerant to adverse rearing conditions silkworm breeds and hybrids by a pre-testing some accessions from the genetic resources and 2. Method of breeding tolerant to adverse rearing conditions silkworm breeds by using polyvoltine strain.

Method of breeding tolerant to adverse rearing conditions silkworm breeds and hybrids by a pre-testing some accessions from the genetic resources.

For the purpose 15 silkworm breeds of the Japanese type, 13 breeds of the Chinese type and 16 F1 hybrids between some of the breeds were used. All the breeds/hybrids were with white cocoon color and uni and bivoltine. The breeds were chosen from the silkworm germplasm, maintained at SAES-Vratza for having comparatively high values of the main quantitative characters (Tzenov and Grekov, 2007). Then the breeds were tested for three times regarding their tolerance to adverse rearing conditions during the 4th and 5th instars (t 28-31 oC, RH 75-80%, feeding amount and rearing space – reduced by 50 %, very reduced ventilation). The breeds who manifested the highest pupation rate under adverse larval rearing conditions were crossed between some of them using the scheme Japanese type x Chinese type and the opposite and the F1 hybrids were further tested also under both standard and adverse rearing regime. Then the hybrids performed the best under the adverse rearing conditions and manifested comparable to the control productivity under standard rearing conditions were chosen and further tested. As a result two new four-way hybrids, namely (KK x Hesa 1) x (Vesletz 2 x Gergana 2), (KK x AS) x (Vesletz 2 x Gergana 2) and the reciprocal crosses, manifested the highest tolerance to adverse rearing conditions along with a satisfactory high productivity under optimal rearing were created (Tzenov and Grekov, 2008, 2009). Both the hybrids have been examined under the system of State variety testing commission and recognized as original.

Simultaneously, each silkworm breed selected by the adverse rearing test was mass reared for 6 generations under adverse conditions and only the individuals survived and having the highest cocoon weight, shell weight and shell percentage were selected for further reproduction. After the 6th generation the breeds have been maintained by batch rearing, following the standard methodology for pure lines.

Method of breeding tolerant to adverse rearing conditions silkworm breeds by using polyvoltine strain.

In this breeding process two uni-bivoltine white cocoon pure lines Super 1 and Hesa 2 and the polyvoltine strain Bonde 517, characterized with yellow-green cocoon color were used.

he breeds Super 1 and Hesa 2 are highly productive with fresh cocoon weight of 2.100 – 2.400 g, shell weight 0.460 – 0.520 g and shell percentage 21 – 22 %. Bonde 517 strain is a typical polivoltine, the cocoons are spindle shaped and flossy, the fresh cocoon weight is 1.000 – 1.100 g, shell weight 0.115 – 0.130 g and the shell percentage is 11 – 12 %. On the other hand this strain has a very high tolerance to adverse rearing conditions, especially high temperature and humidity and it is also comparatively resistant to NPV.

The first step of the breeding process was making F1 and F2 crosses of Super 1 x Bonde 517 and Hesa 2 x Bonde 517. In F2 there was segregation in colored and white cocoons with different shape and texture (Tzenov at al., 1997, 1998, 1999, 2000). Seven male cocoons out of 32 kg cocoons obtained per each cross, having white color, elongated (oval) shape, and similar to those of the uni-bivoltine line texture were selected and mated with selected females of the lines Super 1 and Hesa 2 respectively. Then the two populations were bred by inbreeding for 6 generations, batch rearing, selection for cocoon color, shape, texture and the main quantitative characters. After that the selection process continued with outbreeding for 8 generations, batch rearing, selection for cocoon color, shape, texture and the main quantitative characters. Finally the new silkworm breeds SB 1 and HB 2 were created. The breed SB 1 is of the typical Japanese type, namely larvae with markings, white and elongated with constriction cocoons. The breed HB 2 is of the Chinese type with plain larvae, white and oval cocoons. The main characteristics of the newly evolved breeds are presented in Table 1to3.

Then we tested the F1 hybrids between the two new breeds under optimal larval rearing conditions (Table 4 and 5.). The results manifested that the two hybrids had significantly lower cocoon and silk shell weight than the control, the hybrid Super 1 x Hesa 2. However we also tried the newly evolved breeds as components of a four – way hybrid SB1xSuper 1 x HB2xHesa 2 and the reciprocal. The four – way hybrids manifested a productivity, comparable to the control (Table 4 and 5.). Both the single and four – way hybrids were also tested under adverse rearing conditions during the last two instars (Table 6) and showed remarkably higher pupation rate than the control. As a result the new silkworm hybrid SB1xSuper 1 x HB2xHesa 2 and the reciprocal cross which is characterized with comparatively good productivity and simultaneously a higher tolerance to adverse rearing conditions was created, tested in the system of State agency for variety testing and recognized as original.

Breeding strains and hybrids for higher silk yield.

For the aims of breeding two new silkworm strains, named B1 and Svila 2 have been created for a period of 7 years selection work. The breed B1 is of the Japanese type, having larvae with markings and elongated cocoons with constriction. The breed Svila 2 is of the Chinese type, with plain larvae and oval cocoons. Both the strains are characterized with cocoon weight 2.100 – 2.300 g, shell weight 0.500 – 0.600 g and shell percentage 24 – 26 %. Then from the silkworm germplasm, maintained at SAES – Vratza four other silkworm breeds have been chosen (Hesa 1 and Vratza 35 of Japanese type and Hesa 2 and Merefa 2 of Chinese type) which performed comparatively the highest silk productivity. Using the 6 strains, 10 new F1 silkworm hybrids were created and tested while the Bulgarian hybrid Super 1 x Hesa 2 and the Japanese hybrid Shunrei x Shogetsu had been used as controls (Table 7 and 8).

The results obtained manifested that some of the new hybrids perform higher values than the Bulgarian control and weree close to the Japanese control as regards the fresh cocoon weight, silk shell weight, shell percentage, fresh cocoon and raw silk yield by one box of eggs and filament weight characters values.

It may be concluded that the best hybrids for higher cocoon and raw silk yield are Hesa 1 x Svila 2 and the reciprocal, B1 x Merefa 2, Vratza 35 x Svila 2, B1 x Svila 2 and the reciprocal cross. Among them the best one are Hesa 1 x Svila 2 and B1 x Svila 2 and their reciprocal crosses having average fresh cocoon weight 2.674 g, silk shell weight 0.632 g, shell percentage 23.64 %, filament length 1347 m, raw silk percentage 42.00 %, fresh cocoon and raw silk yield by one box of eggs 43.88 kg and 7.57 kg respectively.

It may be concluded that the two new Bulgarian hybrids have a productivity, comparable with those of the Japanese hybrid Shunrei x Shogetsu, recognized as the best world standard.

Breeding sex-limited for larval markings and cocoon color strains as parents of commercial F1 hybrids, tolerant to adverse rearing conditions and hybrids, with high cocoon and silk productivity.

Breeding sex-limited for larval markings strains as parents of commercial F1 hybrids, tolerant to adverse rearing conditions.

The aims of the breeding process were three fold, viz. To create 4 new silkworm breeds, sex – limited for larval markings as analogues of ordinary breeds, characterized with higher tolerance to adverse rearing conditions; To use the newly bred strains as parents of four – way hybrid in order to obtain higher cocoon yield and fecundity at the P1 egg category level and The parents of the F1 hybrid (P1) to be sex – limited for zebra larval markings in order to make easier the sex discrimination.

The method of creation the 4 new sex – limited for larval markings breeds was as follows (Tzenov & Guzman, 2004, Tzenov, 2005):

1. Initial population: cross between females of sex limited for larval markings strain, received from Japan and males of strain, tolerant to adverse rearing conditions;

2. Backcrosses for 9 generations, using as male parent the tolerant to adverse rearing conditions strain, mass rearing;

3. Backcrosses for 3 generations, batch rearing;

4. New sex – limited breed.

The newly created sex – limited breeds have the following morphological characteristics:

SN1: the females are zebra, the males are with normal markings. The cocoons are white, elongated with constriction.

Iva 1: the females are with normal markings, the males are plain. The cocoons are white, dumbbell with high constriction.

Magi 2: the females are zebra, the males are plain. The cocoons are white in color, oval.

Nova 2: the females are with normal markings, the males are plain. The cocoons are white in color, oval.

In order always in the P1 generation to have females with zebra markings we performed only the crosses SN1 x Iva 1 and Magi 2 x Nova 2 (Tzenov, 2005, 2008). The average number of normal eggs in a laying in the 4 pure breeds was 618, while in the P1 crosses it’s 664. The performance of the pure breeds, their P1 crosses and the F1 commercial hybrid are given in tables 9 and 10

It is evident that both P1 and F1 hybrids manifest a comparatively high productivity. The F1 hybrid SN1 x Iva 1 x Magi 2 x Nova 2 was also tested under adverse rearing conditions (table 6) and showed a comparatively high pupation rate, compared with the control. The hybrid has been tested in the system of the State variety testing commission and approved as original.

It may be concluded that by breeding of 4 new sex – limited for larval markings strains a higher egg production efficiency by means of higher cocoon yield and fecundity at the P1 egg category level was obtained and a F1 four – way hybrid, having a high productivity, combined with a higher tolerance to adverse larval rearing conditions was created.

Breeding sex-limited for cocoon color strains as parents of commercial F1 hybrids, with high cocoon and silk productivity.

Three silkworm breeds were used, namely the Japanese breed D 50 and the Bulgarian breeds Super 1 and Hesa 2. The Japanese breed D 50 was received from the Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka, Japan. The breed D 50 is genetically sex limited for cocoon color – the female cocoons are yellow and the male cocoons are white. The breed has larvae with ordinary markings and elongated cocoons with constriction. On the other hand the breed performs a very low productivity and the population contains the so called gene „translucent skin larva”. It’s known that this character is controlled by over 23 alleles, located at different chromosome loci. The „translucent skin larva” gene is also lethal or it determines sterility in the female moth. In the case of the breed D 50 the females with translucent skin lay eggs which embryo dies later on. In the D 50 breed population about 50 % of the larvae are with translucent skin and the rest have normal skin.

The breed Super 1 is of the Japanese type, having larvae with markings and spinning white cocoons with elongated shape. The breed Hesa 2 is of the Chinese type, having plain larvae and spinning white cocoons with oval shape. Both the breeds are highly productive and used as parental lines of several Bulgarian F1 commercial silkworm hybrids.

The breeding target was to create two new breeds having the same morphological characters and similar productivity as the original Bulgarian breeds Super 1 and Hesa 2, but sex limited for the cocoon color. For the purpose female individuals of D 50 strain were crossed with male individuals of Super 1 and Hesa 2. The breeding scheme is given in Fig. 1. The first generation (G1) was mass reared as mixture of 60 laying (one laying are the eggs laid by one mother moth) separated in 10 replications. In G1 all the female individuals spun only yellow cocoons and all the males – white cocoons which proved the stable inheritance of the linked with the W chromosome „y” allele, responsible for yellow haemolymph and yellow cocoon color. From the cocoons obtained, females with golden yellow cocoon color were selected and then measured individually to detect their fresh cocoon and silk shell weights and the shell ratio. The individuals having the highest parameters were selected and then mated with selected male individuals from the breeds Super 1 and Hesa 2. A random cocoon sample had been taken in order to check the silk reeling parameters of the population. The second generation (G2) obtained was reared and maintained by the same method and then crossed again with selected males of Super 1 and Hesa 2. During the fifth instar the larvae of the population D 50 x Hesa 2 G2 were separated into plain and with markings while only females from the plain larvae group were used for further breeding. Then in the 3rd generation (G3) a separate batch rearing was performed where the eggs of each silkworm moth were grown separately. Each population was reared in a volume of 32 laying each one having 200 larvae counted after the 2nd molt and then a selection of the 10 best laying regarding the pupation rate, cocoon, silk shell weights and shell ratio was implemented. The cocoons of the chosen 10 laying were measured individually and then only 20 female and 20 male cocoons from each laying, having the highest parameters were selected.

The selected cocoons from each laying were sib - mated in order to obtain the 4th generation (G4) which was inbreed. The purposes of this inbreeding were first to check the population uniformity reached at this stage through detecting the segregation after the inbreeding and secondly to reject the laying which manifest the „translucent skin larva” character. The fourth generation was reared in a volume of 32 separate batches, each 4 originated from one laying of G3 after inbreeding. After rejection of several 4 – laying batches manifesting the „translucent skin larva” character the rest laying/individuals were object of the same selection procedure like in G3. The selected female individuals of G4 were again crossed with males of the breeds Super 1 and Hesa 2 respectively in order to obtain the 5th generation (G5). Then the 5th generation was further reared and all the morphological and economically important parameters were detected.

During the larval rearing of each selection generation, separate batches of the breeds Super 1 and Hesa 2 have been also reared in parallel in order to make comparison between the productivity of the newly selected populations and the original breeds. The data obtained were processed statistically using the well recognized methods. Then in G 6 generation we repeated the inbreeding in order to obtain G 7, which generation was again crossed with males of Super 1 and Hesa 2 respectively. The 8th generation we already considered as a new breed and gave names of the newly bred strains as L 1 (D 50 x Super 1) and L 2 (D 50 x Hesa 2).

Hybrids between the new breeds L 1 and L2 as well as four – way hybrids L1 x Iva 1 x L2 x Nova 2 and the reciprocal crosses have also been produced and tested.

It is evident from the data shown in Table 11 that the breeds L 1 and L 2 still manifest lower values of the basic productive characters than those in the strains Super 1 and Hesa 2. May be an other reason is the depression which causes the translocation of the Y allele on the W chromosome (Kimura at al., 1971; Yamamoto, 1989; Datta at al., 2001). On the other hand the productivity of the newly selected breeds is much higher if compared with the Japanese sex limited strain D 50. This picture is however different in the new hybrids, compared with the control.

The data presented in Table 12 show that all the four sex limited for cocoon color silkworm F1 hybrids display a higher pupation rate than the control. The hybrid L1 x L2 and the reciprocal has fresh cocoon weight, silk shell weight and shell ratio very close to the control. Both new four way hybrids manifest lower than the control values of the three characters studied, which we explain by the participation in them as mail parents of the sex limited for larval markings breeds Iva 1 and Nova 2, having a higher tolerance to adverse rearing conditions, but a little lower productivity.

It may be concluded that we created 4 new sex – limited for cocoon color silkworm F1 commercial hybrids which manifest a pupation rate and productivity, comparable with those of the control, the hybrid Super 1 x Hesa 2.

REFERENCES

Datta, R. K., Basavaraja, H.K., Mal Reddy, N., Kalpana, G.V., Joge, P.G., Palit, A.K., Jayaswal, K.P. (2001)„CSR8” Sex limited bivoltine breed. A boon for graineurs. Indian silk 39 (11): 5-7.

Kimura, K., Harada, C., Akai, H. (1971) Studies on „W” chromosome translocated in yellow blood gene in silkworm, Jap. J. Breed. 21: 199 – 203.

Tzenov, P., Y.Natcheva, N.Petkov (1997) Study of on the cocoon coulor and cocoon shape characters inheritance in F1 crosses between in bivoltine and multivoltine races of the silkworm Bombyx mori L., Bulg. J. of Agric. Sci., 2, 181-185.

Tzenov, P., Y. Natcheva, N. Petkov (1998) Inheritance of the larval marking character in hybrids between multivoltine and unibivoltine silkworm, Bombyx mori L., races, Bulg. J. of Agric. Sci., 4, 3, 373-378.

Tzenov, P., Y.Natcheva, N.Petkov (1998) Cocoon shape inheritance in hybrids between multivoltine and uni-bivoltine silkworm, Bombyx mori L. races. Bull. Ind. Acad. Sericultural, vol. 2(2), 8-15, India.

Tzenov, P., N.Petkov, Y.Natceva (1999) Study on the inheritance of food ingestion and digestion in hybrids between univoline and multivoltine silkworm, Bombyx mori L., races, Sericologia, 39 (2), France.

Tzenov, P., Y.Natcheva, N.Petkov (1999) Study of the cocoon color segregation manifested in crosses between uni-bivoltine and multivoltine silkworm, Bombyx mori L. rаces, Sericologia, 39 (3), France.

Tzenov, P., Y.Natcheva, N.Petkov (2000) Study on the cocoon color segregation manifested in hybrids between uni-bivоltine and multivoltine silkworm, Bombyx mori L. races, Sericologia, 40 (1), 67-73 (France).

Tzenov P. & Z.I. De Guzman (2004) Breeding the new Bulgarian sex-limited for larval markings silkworm Bombyx mori L. commercial hybrid Ze/4 and study on its performance in the Philippines and Bulgaria, Sericologia 44(3), 297-312. (France)

Tzenov P. (2005) Study on the larval markings inheritance in some four-way hybrids between sex-limited for larval markings silkworm, Bombyx mori L. breeds. In: “International Workshop on Revival and Promotion of Sericultural Industries and Small Silk Enterprise Development in the Black & Caspian Seas Region”, Tashkent, Uzbekistan; 415-419.

Tzenov P. (2005) Breeding of new silkworm, Bombyx mori L. sex-limited for larval markings analogues of parental pure lines by the method of back crosses. In: “International Workshop on Revival and Promotion of Sericultural Industries and Small Silk Enterprise Development in the Black & Caspian Seas Region”, Tashkent, Uzbekistan; 419-424.

Tzenov P., D. Grekov (2007) Breeding of New Tolerant to Adverse Rearing Conditions Silkworm, Bombyx mori L. Four-way Uni-bivoltine Commercial Hybrids, Scientific conference on mountain agriculture, Troyan, May 2007.

Tzenov P. D. Grekov (2008) Development of methods for breeding new silkworm, Bombyx mori L. commercial hybrids tolerant to adversе rearing conditions. Annals of agrarian science, vol. 6, № 2, 71 – 76.Georgia.

Tzenov P., D. Grekov (2009) Breeding of new tolerant to adverse rearing conditions silkworm, Bombyx mori L. four – way uni – bivoltine commercial hybrids. In: Application of Biotechnology in Sericulture, 243 – 252. Bangalore, India

Tzenov P. (2008) Heterosis Expression in Some Main Quantitative Breeding Characters in Four – Way Sex-Limited for Larval Markings Silkworm, Bomby mori L. F1 Hybrids, 21st Congress of the International Sericultural Commission, 3 – 6 November 2008, Athens, Greece.

Yamamoto, T. 1989. Breeding of sex limited yellow cocoon races of silkworms by chromosome manipulation. Farming Japan 23 (5): 42 – 48.

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DIVERSITY OF INSECTS IN THE MULBERRY ECOSYSTEM

A.Mahima Santhi and S. Prasanna Kumar

In this issue we present a very interesting paper by two entomologists of South India. The paper deserves special attention primarily because of its ecological approach to sericulture and entomological perspective to pest insects. Even though the primary responsibility of an agricultural entomologist is to device means to eliminate insects designated crop pests and to protect those designated economically important; the ecological balance between the pest, other (neutral) insects and the crop environment deserve his/ her attention in a long term perspective. This paper is notable at a time when such studies (at least in Moriculture) are becoming increasingly rare.

Dr. A. Mahima Santhi is a scientist with Central Silk Board, India. A post graduate in Agriculture from Tamil Nadu Agricultural University (TNAU), she earned her PhD in Agricultural Entomology from Manonmaniyum Sundaranar University, Thirunelveli, India. She holds more than eighteen years of research experience in sericulture and entomology under CSB. Currently she is heading the technical wing of Kerala State Sericulture Cooperative Federation (SERIFED) as its Deputy Director.

Dr. S. Prasanna Kumar is Professor & Head, Department of Zoology and Dean of Sciences, Scott Christian College, Nagercoil, India. A PhD in Zoology, he has more than thirty years of research and teaching experience in Entomology.

INTRODUCTION

The perennial nature of mulberry combined with monocultural practices, harbours several pests throughout the year with seasonal variations (Rangaswamy et al., 1976). The production of appreciable quantity of quality mulberry leaf is often hampered by insect pests belonging to large number of insect orders. Apart from insect pests, predators, parasitoids, naturals and detrivores also survive on mulberry plant. Studies on diversity are the preliminary for any management work. . Narendran (2001) explained that taxonomy is the foundation of biodiversity. Hence a survey was conducted in mulberry ecosystem to survey the diversity of the insects. The taxonomic diversity of the insect communities was worked out in the mulberry ecosystem.

MATERIALS AND METHODS

Survey on the insect diversity was conducted at Nagercoil, South India for continuous two years. The details of materials and methods are described here.

Insect assessment

The mulberry garden was divided into five sub plots, four at corner, and one at the centre. From each sub plots ten plants were selected at random for the observations. Thus 50 plants were observed every fortnight for two years. The number of mealy bugs, grasshoppers, scales, whiteflies, thrips, leafhoppers, bugs etc., feeding on the plants were counted. The total number of predators and parasitoids present on each selected plant were counted. Ants attending mealy bug populations were also recorded. Other insects such as butterflies, cockroaches present on the plant at the time of observation were also recorded. The soil insects such as carabids, termites were counted around the selected plants using Berlese funnel method. The average of the counted insects per ten plants was treated as one sample. The insects were collected, observed and unknown insects were preserved for identification according to Schauff (2002). The insects of various orders of class Insecta were distinguished.

RESULTS

The insects collected were identified and grouped in different orders of class Insecta according to Ambrose (2004). An average of 3388 insects was recorded per sample. Insects belonging to ten orders were recorded. The order Hemiptera recorded 60.86 per cent of total insects and order Hymenoptera recorded 22.05 per cent of insects. The order Coleoptera recorded 8.65 per cent. Other orders such as Isoptera, Lepidoptera, Dictyoptera, Odonata, Orthoptera and Thysanoptera accounted the rest. The distribution is detailed in chart.1

The details of insects recorded were given below as orderwise

Order: Hemiptera

It was the largest hemimetabolous orders with piercing and sucking mouthparts, with two sub orders, Homoptera and Heteroptera. Insects from both suborders were observed in the field.

Suborder: Homoptera

Insects which do not possess scutellum and has uniform leathery forewings are homopterans. Insects observed from this orders were herbivores. Important ones are detailed below.

Family: Pseudococcidae

Pseudococcids, generally called mealy bugs were the dominant insects. Their body was covered by mealy coating. Eggs were laid in loose cottony sac. Young ones were gregarious. Female were wingless and males winged. These mealy bugs secreted honey dew hence attended by ants. These ants protected mealy bugs from natural enemies. In the present study three species of mealy bugs were observed in the field. The mealy bugs recorded were.

a. Maconellicoccus hirsutus

These mealy bugs were present throughout the year except rainy months followed by winter season. The population was low during rainy season. The mealy bugs prefered tender leaves and twigs. Continuous feeding by mealybugs caused severe tukra symptoms.

b. Ferrisia virgata

The tailed mealy bug, which is a polyphagous pest, also infested young mulberry leaves. Their occurrence was very meagre to show any visible symptom, in few cases young shoots tips dried due to continuous feeding.

c. Planococcus citri

This was a serious pest found almost in all the months in the second year and summer months in the first year. Young ones fed on tender leaves and caused curling of leaves but not clustered like tukra. The grown up ones were seen feeding on the nodes and uniformly distributed throughout the stem. On continuous feeding the leaves become yellow and withered off. When there was severe feeding the terminal bud was killed which caused the sprouting of ancillary bud. Severe damage made the stem to dry. The mealy bugs were attended by black ant, Camponotus compressus.

d. Paracoccus marginatus

Recently papaya mealy bug incidence was noticed on mulberry crop in western parts of Tamil Nadu and Palghat district of Kerala. The papaya mealy bug is found on leaves, stem and twigs. Adult females are yellowish with short waxy filaments around the margin. The dispersal stage is the first instar crawler. The mealy bug injects a toxin as it feeds on leaves, which results in chlorosis (yellowing), stunting, deformation, early leaf drop, and buildup of honeydew. Sooty mould growing on honeydew excreted by the mealy bugs interferes with photosynthesis. Heavy mealy bug infestation kills the plants.

Highly polyphagous in nature.

Family: Margarodidae

The insect Icerya aegyptiaca was seen feeding from undersurface of the leaves. These insects were seen in groups or single. These bugs were bigger in size and orange coloured with black legs. The body was covered with white mealy waxy strands. Eventhough the pest was seen in majority of the months, the damage symptom was not serious. The population was higher during summer months.

Family: Aleyrodidae

Aleurodicus dispersus, the white fly were minute active whitish insects resembling tiny moths. The body and wings were covered with white powdery coating. The eggs were laid in irregular spirals. The white nymphs and adults were seen on lower surface of leaves. The desapping of leaves depleted the nutritive value of leaves. The incidence was noted from late January to early April.

Family: Membracidae

The cow bugs Oxyrachis tarandus were seen feeding on tender shoots. The nymphs were attended by ants. Their occurrence was very meagre. Small specks were seen at the feeding site.

Family: Coccidae

The black scales, Saissetia nigra were seen on stem and on lower side of the leaves. The occurrence was noted from January month to May. No severe damage noticed.

Family: Cicadellidae

The leaf hopper, Empoasca flavescens, adults, and nymphs fed on tender leaves and caused “hopper burn” symptoms. They were very active and jump, can move sideways. The incidence was noted during July to October months. The insect population was very low to cause economic injury.

Suborder Heteroptera

Family: Pentatomidae

The shield bug, Scutellera nobilis was seen very rarely on mulberry and did not cause much damage.

Family: Reduviidae

The assassin bug, Eirantha armipes were seen during rainy months June-July. This was an effective predator.

Order: Hymenoptera

Family: Formicidae

Beneficial interaction existed between the mealy bug and ants. The dominant M. hirsutus population was heavily influenced by ant population. The predator population in the ant attended colonies was significantly lower. Ants were seen attending mealy bug colonies.

Family: Sphecidae

The mud dauber wasp, Ammophila procera were seen very rarely on mulberry leaves. The females hunt for arthropod prey which serves as food for their offspring.

Family: Encyrtidae

The small parasitoid, Leptomastix dactylopii was rarely seen in the garden. But the parasitized mummies of mealy bug were seen during non-rainy months.

Order: Coleoptera

Coleopterans are the insects with biting and chewing mouth parts with hard exoskeleton. Forewings were hardy and hind wing membranous.

Family: Cerambycidae

The stem girdler, Sthenias gristator was seen during February month of the first year. The adult beetle girdled the young green branches of the mulberry plant and caused drying of the twig. The bark and wood up to the centre were cut by powerful mandibles and in few plants entire twig was cut into two bits.

Family: Curculionidae

Ash weevil, Myllocerus discolor and M. viridanus were seen on mulberry leaves. The presence of this beetle was recorded throughout the year. Their occurrence was slightly higher during summer months. Damage symptoms were not severe.

Family: Scarabaeidae

The dung beetles or dung rollers, Scarabaeus sp were seen on the soil during summer months. They produced dung balls for egg laying. They are grouped under scavengers.

Family: Carabidae

The ground beetle Carabus nemoralis were found throughout the year in the soil. The beetles were mainly predators.

Family: Coccinellidae

Two predatory beetles were recorded. Nephus regularis (Sic.) was the common predominant predator seen feeding on mealy bugs. They were seen inside the tukra curls. The grubs were black coloured with white mealy coating seen inside the tukra curls feeding on mealy bugs. Adults were very small oval shaped brown coloured beetles. The population of this beetle increased with increase in mealy bug population. The activity of beetles was not seen on tukra affected branches with ants.

Another yellow lady bird beetle recorded was Illeis cincta. The yellow coloured grubs and adults were seen on plants feeding on powdery mildew growth on leaves. Their occurrence was higher during winter months.

Order: Thysanoptera

Small insect with rasping and sucking mouth parts.

Family: Thripidae

The thrips, Pseudodentrothrips mori injured the epidermal tissues of leaves and desapped Leaves showed streaks in the early stages and blotches in the later stages. Leaves became brittle and were unsuitable for feeding silkworms. In severe case of attack leaves whither and dried. The attack was seen during May and June of the first year. The second attack was during December to February. Then the attack was repeated during May and June in the second year.

Order: Orthoptera

Medium sized insects with mandibulate mouthparts, the hindlegs are enlarged facilitating jumping.

Family: Acrididae

The short horned grasshopper Neoorthacris nilgriensis or wingless grasshopper was present throughout the year. The population showed slight increase during summer months when other plants dried without irrigation. The insect had shorter antennae and ovipositor. The wings were not present.

Other insects of this order, long horned grasshopper, Tettigonia viridisima of Tettigonidae and field cricket, Gryllus sp. of Gryllidae were also present in the garden.

Order: Isoptera

Soft bodied, social and polymorphic winged species living in large colonies, with biting mouth parts.

Family: Termitidae

The termites Odontotermes sp. feed upon roots and barks of young and old plants. Severe attack leads to death of plant. These termites build colony structure and live socially with workers, soldiers and queen. The presence of termite was higher during summer months.

Order: Lepidoptera

Lepidopterans are holometabolous insects, adults brightly coloured, winged insect with long tubular suctorial mouthparts. The larvae are soft bodied caterpillars with biting mouth parts. The pupae are generally enclosed in a cocoon.

Family: Pyraustidae

Diaphania pulverulentalis, the leaf roller of mulberry, incidence were recorded during September and October months. The larvae damaged by folding the leaves and by webbing the tender shoots. Early instars fed from inside the web and skeletonize the leaves. Later instars fed the tender leaves voraciously. Larval feeding caused qualitative and quantitative loss of leaves.

Other insects of Lepidoptera present were Eurema hecabe of Pieridae, Catochrysops cnejus of Lycaenidae and Danaus plexippus of Danaidae. They were neither harmful nor useful to mulberry.

Order: Odonata

The dragonfly, Libellula quadrimaculata of Libellulidae and Damselfly, Protoneura sp of family Protoneuridae were commonly seen in the mulberry leaves. These insects were general predators.

Order: Dictyoptera

Suborder: Mantodea

The preying mantis, Mantis religiosa of family Mantidae was recorded. They were effective general predators.

Suborder: Blattaria

The field cockroach Blattella sp of family Blattellidae were seen scavenging on mulberry plants. The insects occupied the tukra curls for shelter.

DISCUSSION

The order Hemiptera was the prominent order. Around 60 to 62 per cent of insects belonged to order Hemiptera. Under Hemiptera order, six homopterans and two heteropterans were recorded. The family Pseudococcidae with four species of mealy bug was the largest family recorded. Next homopteran recorded in the garden was whitefly. Hymenoptera was the second dominant order in the garden. Ants were found in association with the homopterans. There was a beneficial interaction between homopterans and ants. The parasitoid of mealy bug Leptomastix dactylopii was also recorded under this order. These insects were used in bio control programmes often in mealy bugs. (Noyes and Hayat, 1988).
The order Coleoptera was the third largest order in the garden. The coccinelids were dominant and seen throughout the year. They were effective predators of soft bodied insects and also feed on fungal growth such as powdery mildew. This was also reported by Joshi et al., (2003). The carabids were found next to coccinellids in the field. Allen (1979) reported carabids as beneficial insects.

Insects of Isoptera, Lepidoptera, Dictyoptera, Odonata, Orthoptera and Thysanoptera were found in mulberry ecosystem. Among these insect orders, Odontotermes obesus of Isoptera, Diaphania pulverulentalis of Lepidoptera and Pseudodentrothrips mori of Thysanoptera were serious pests of mulberry ( Sathya prasad et al., 2000 and Dandin et al., 2001).

The trophic interaction between plants, herbivores, natural enemies and others were studied in the mulberry field and detailed in chart.2. In the present study 68 per cent of phytophagous, 4 per cent of predators, 25 per cent of ants, 1.5 per cent of scavengers, and 1.5 per cent of neutrals were recorded. These studies should be done in all mulberry ecosystems. The natural enemies should be preserved in the garden. The balance between phytophagous insects, natural enemies, detrivores, and neutrals should be maintained for a successful mulberry crop.

REFERENCES

  Allen, R.T. 1979. The occurrence and importance of ground beetles in agricultural and surrounding habitats. In T.L. Erwin, G. E. Ball and D.R white head (eds) Carabid beetles their evolution, natural history, and classification. W.junt, The Hague, The Netherlands. 485-505pp
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Is Perfect Research Possible?

GK. Rajesh
Recently I was asked to write an essay, expressing my views on the statement "There Is No Hope of Doing Perfect Research" by the selection panel of a content writing employer. I gave them the following answer, which I wish to share with my readers.

   The given question on research can be put to any ‘human activity’ and still be found equally difficult to answer. Is it possible to do anything perfect? The quickest possible response is ‘no’. A little reflection will show that this answer in the negative has nothing to do with the activity under question. It is the perceived notion of the word ‘perfect’ that drives the respondent towards the negative answer because anything perfect is understood to be ‘nearly impossible’ let alone research. Usually ‘perfect’ as an adjective is used for harmless, jocular exaggeration of the quality under question. For example the expressions ‘a perfect fool’ or ‘perfect nonsense’ do not mean the qualities under question to be absolute. They are rather cursory and superficial remarks than conclusions of any serious investigation. One rarely encounters such expressions in scientific literature. Similarly the expression “perfect research” is not found in any standard literature. Instead, terms such as reliability, validity, credibility transferability and trustworthiness are used to indicate various desirable qualities of research work (Golafshani 600). Hence, in this essay the term ‘perfect’ will be used to collectively represent these terms.

   The term ‘research’ is defined as follows: “Scientific or scholarly investigations especially study or experiment aimed at the discovery, interpretation or application of facts, theories, or laws” (Allen1188), “Careful study or investigation, especially in order to discover new facts or information” (Hornby 996), “Diligent, protracted investigation” (“Webster’s” 1071). Thus research constitutes investigation and discovery/ interpretation/application of knowledge. A research may be safely regarded as fruitful if it results in the discovery of an object or a procedure which it is intended for. To call it perfect demands more assessment with regard to the quality of the discovery (whether it has all the qualities, excellences or elements that are requisite to its nature or kind), the procedure adopted (whether without fault or defect) and the way in which it was executed (whether economic and without negative externalities). For example the discovery of penicillin, in spite of its great utility may not be called perfect research since it was rather an accidental finding than result of systematic investigation originally intending to its discovery. Alexander Fleming wrote “… I certainly didn’t plan to revolutionize all medicine by discovering the world’s first antibiotic, or bacteria killer, but I suppose that was exactly what I did …” (qtd. In Wikipedia.org). The discovery of molecular structure of DNA traced from its origins in 1868 by Friedrich Miescher to the celebrated work of Watson, Crick and Wilkins in 1962 could be considered as a continuum of perfect research. While quantitative research1 is more amenable to such assessment, qualitative research2 is not.

   Two case studies on my own research cited here are examples of quantitative research with mixed results. The first was my Master’s Degree dissertation work on temperature induced protein synthesis in silkworms (Rajesh GK, “Induction of Heat Shock”). Heat shock proteins are specialized proteins which are synthesized in living cells under stress of any kind. They are known to perform protective actions within the cell under trauma. My intention was to study the threshold temperature which triggers heat shock response in silkworms. The theoretical premise in which the experiment was set was excellent and the research question meaningful. But the work lacked in focus. In my slightly over enthusiastic mindset I set a very ambitious objective, not only to track down heat shock proteins but also to assess their differential expression in two breeds of silkworms. The experiment proved to be too big to fit in the time span permitted for an MSc dissertation. Though I could complete the experimental part as per my original design and with a high level of accuracy3 I could not subject the huge data generated into fruitful analysis and interpretation. Nevertheless the fraction of data that I could use was systematically put together into a neat report which received good remarks. I realized my mistake only at the end of the work. I had ben simply over ambitious and neglected the importance of focusing on the specific problem and conceptualizing the research work in a practical manner. I am sure, given more time to understand my mistake, the work could have been more systematically organized and made perfect. After all the empirical investigation was done perfectly, evidenced by the concordance of observations in replications.

   The second example is of my MPhil (Economics) dissertation on factors determining adoption of a (new and improved) technology by sericulture farmers in India (Rajesh GK, “Diffusion”). I investigated the reasons why a superior silkworm hybrid had not diffused well in the country in spite of great efforts from the government for more than a decade. Being better informed and having grown wiser out of the previous experience, I was more vigilant and pragmatic this time. After an exhaustive literature survey and expert consultation a very specific and real world problem was spotted down. The proposal was presented before a distinguished panel and finalized after incorporating suggested modifications. The theoretical background was strong and the study was conceived with clarity. The empirical investigation was planned to the minutest detail and the survey questionnaire perfected after a mock survey. The data was subjected to rigorous statistical analysis and the findings were written down systematically into a comprehensive yet concise report. The dissertation was awarded with an A-plus and I received an almost flattering comment from the external jury (which I consider I am not entitled to). But I do not deem the work perfect. Once the survey was completed I realized that in spite of all my preparatory work the sample selected by me was not quite representative of the country and the sample size too small given the diversity of technology adoption strategies employed by the target population. Since it was a time bound assignment I could not extend my survey to capture the diversity. I am sure that it would make a perfect piece of research if repeated with a bigger and different set of samples.

   My own imperfect researches are not convincing proof to conclude that there is no hope for perfect research. I do not agree to the statement ‘there is no hope for perfect research’; it could be so only if the term ‘perfect’ is taken on its ‘utopian sense’ of ‘ideal’. Then it is as good (or bad) as saying- anything human is imperfect. The European Commission’s Expert Group on Assessment of University Based Research commented

   “There is no single set of indicators capable of capturing the complexity of research and research assessment. There is no such thing as a perfect indicator; all indicators have their own specific strengths and weakness, and assessment exercises have to take this into consideration from the outset … (“European Commission” 12).”

If there is no perfect indicator for research assessment there is no point in looking for perfect research. Research is the life blood of human development; it is relentless quest for truth. When truth itself is subject to change, there is no meaning in idealizing research, which is one of the means for attaining it. According to Schwarts, “… research is immersion in the unknown. We just don’t know what we are doing. We can’t be sure whether we are asking the right question or doing the right experiment until we get the answer or the result …” (1771). He calls this “productive stupidity” and concludes that “The more comfortable we become with being stupid, the deeper we will wade into the unknown and the more likely we are to make big discoveries”. Why waste time, thinking whether stupidity is perfect!

NOTES

1. Patton defines quantitative research as “use of standardized measures so that the varying perspectives and experience of people can be fit into a limited number of pre-determined response categories to which numbers are assigned” (qtd. In Golafshani 598)
2. Strauss and Corbin define qualitative research as “any kind of research that produces findings not arrived at by means of statistical procedures or other means of quantification” (qtd. In Golafshani 600)
3. Accuracy with respect to raising the biological specimens, adhering to the scientific standards and in quantifyication and electrophoretic separation of proteins.
Bibliography
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