CSRTI advises farmers to use only recommended pesticides to ensure spinning of cocoons by silkworms

After subjecting 90 samples of silkworms, soil, and mulberry leaves to testing and analysis, it was found that the use of unrecommended pesticides, as well as other spurious chemicals on mulberry crops, was the reason for the silkworms failing to spin a cocoon, says CSR&TI Director Dr. Gandhi Doss

Scientists from CSR&TI including its Director Dr. Gandhi Doss (Centre) addressing a press conference in Mysuru on Tuesday, November 21. | Photo Credit: M.A. Sriram

Scientists from the Central Sericultural Research and Training Institute (CSR&TI) in Mysuru have urged farmers to use only the pesticides recommended by the institute to tackle the problem of silkworms failing to spin cocoons.

After noticing a rise in the complaints of silkworms failing into spin cocoons, scientists from CSR&TI visited several parts of Karnataka and neighbouring States and collected more than 90 samples of silkworms, soil, and mulberry leaves. After subjecting them to testing and analysis, it was found that the use of unrecommended pesticides, as well as other spurious chemicals on mulberry crops, was found to be the reason for the silkworms failing to spin a cocoon, said CSR&TI Director Dr. Gandhi Doss while addressing a press conference in Mysuru on Tuesday, November 21.

He regretted that sericulture farmers were using a variety of chemical pesticides that had not been recommended by the institute for mulberry cultivation. The chemical residue of the pesticides and other agrochemicals affects the nervous system and other health conditions of the silkworm, leading to its inability to spin a cocoon, he said.

Responding to queries from reporters, Dr. Doss said about 2 to 5 per cent of the sericulture farmers had been plagued by the problem of non-spinning of silkworms, affecting about 20 per cent of their cocoon crop.

Though the complaints of some silkworms failing to spin cocoons were first heard about five years ago, their number had increased lately, he said while asking the farmers to contact CSRTI for guidance on using recommended pesticides.

CSR&TI scientist Dr. K.B. Chandrashekar, who was also present on the occasion, said the phenomenon of silkworms failing to spin a cocoon noticed in several areas across South India is also accentuated by climatic conditions.

Scientist Dr. Mahiba S. Helen said the issue of non-spinning of silkworms is also noticed when a farmer changes the crop. Citing the case of a farmer in Chamarajanagar, who shifted from tomato crop to mulberry, the scientist said the residual toxicity in the soil due to the use of pesticides for the earlier crop will also impact the subsequent mulberry plantation.

However, scientist C.M. Babu pointed out that soil toxicity can be addressed by the use of recommended pesticides in the subsequent mulberry crops.

Scientists Dr. R. Bhagya and Dr. Balasaraswathi pointed out that chemical pesticides sprayed on crops in adjoining agricultural fields may also have an impact on the mulberry plantation.

The scientists favoured the use of pesticides recommended by CSR&TI and other institutions like Silkworm Seed Technology Laboratory (SSTL), Bengaluru, Karnataka State Sericulture Research and Development Institute (KSSRDI), Bengaluru, and Andhra Pradesh State Sericulture Research and Development Institute (APSSRDI) in Hindupur in neighbouring Andhra Pradesh.