‘ILAMATHI’- A Phytojuvenoid formulation for Silkworm

Dr. N. Chandramohan, Professor (Retd), Dr. C. A. Mahalingam, Professor and Dr.S. Subramanian, Principal Scientist (at IARI, New Delhi)

The phyto juvenoid- Ilamathi developed by TNAU

Sericulture is a remunerative agro enterprise providing livelihood to millions of people in India. In order to meet our growing demand, the production and productivity of silk has to be improved.

Among various technologies to improve the cocoon productivity, application of juvenile hormone (JH) on silkworm is practiced in several silk producing countries.  They tend to keep the Fifth instar silkworm young for a specified period by extending the larval period and increase the silk secretion. It postpones the spinning stage by few hours.

Altosid, R394, Manta and ZR512 are some of the commercial synthetic JH analogues used in countries like Japan and China. Synthetic JH analogues are hitherto not available for use by sericulturists in India. Moreover, the import of the chemical is cost prohibitive. Hence there is a need for identification of cost effective JH formulation for improving silk productivity.

Department of Sericulture, Tamil Nadu Agricultural University, Coimbatore has screened several plant products and short listed fewer plants possessing JH activity, (Phytojuvenoid) against silkworms. Extraction procedures were standardized and a novel botanical formulation was developed. Comparing the growth of silkworm to different phases of moon, the new formulation has been named ‘ILAMATHI’ (young moon) as it keeps the larvae young.

The botanical formulation was found to increase the larval duration, cocoon weight and there by yield of 25.16 percent followed by a collective analysis of research station and OFT showed an increase in cocoon and over control in OFT research station 9.15% cocoon yield was realized by farmers in On Farm Trials.

For treating 100 dfls (40,000 larvae) an additional cost of Rs. 165 was required. An additional yield of 9.48 kg of cocoon was harvested with a monetary return of Rs. 848 for every 100 dfls by was of phytojuvenoid treatment. The net gain is Rs. 684 with a increment cost benefit ratio (ICB) of 1:5:14.

Application Method
Product	TNAU Botanical formulation Ilamathi
Containers size	10ml vial
Time of application	2nd day of fifth instar larvae
Dose	1ml / litre of water
Concentration	1000 ppm

1.      It is applied on mulberry leaves after dissolving 5ml of Illamathi in five liters of water, and feed to 2 day old 5 instar worms.

2.      Spray fluid is applied uniformly over the shoots/leaves (in tray rearing) with help of an atomizer (or) garden sprayer and allowed to dry for 30 minutes.

3.      Treated leaves are given as two first feeding for the two days old fifth instar.

Caution

1.      Don’t postpone the Illamathi application beyond second day of fifth instar.

Merits of ‘ILAMATHI’

1.      Application of Illamathi gives an additional cocoon yield of 8kg/100 dfls.

2.      It also reduces grasserie disease in silkworm.

3.      The application of ‘ILAMATHI’ is safer to silkworm and it will not hinder the growth and development of the larvae. Besides, the formulation also confers resistance to BMNPV infection. Hence application of ‘ILAMATHI’ is a novel technology to boost the silk yield and silk productivity to the farmers of Tamil Nadu.