Effect of Feeding Pesticides Sprayed Mulberry Leaves on Rearing Parameters of Silkworm

Abstract

A bioassay study was conducted to test the effect of feeding pesticides sprayed mulberry leaves on silkworms. The pesticides that are used to control mulberry pests were selected with the recommended dose as per the label claim and were sprayed on mulberry plants and fed to silkworms (FC1) at 5, 10, 15 and 20 days after spraying (DAS) to know their impact on the growth of silkworms. The results revealed that among the five pesticides tested, Azadirachtin 1 per cent (2 mL/L) and Chlorfenapyr 10 SC (1.5 mL/L) were highly toxic to silkworms with maximum larval mortality of 100 and 23.5 per cent even at 10 days after spray, but less toxic at 15 days after spray, respectively. However, the pesticide Orgomite (2.5 mL/L) a botanical formulation recorded the least mortality of silkworm (7.83%) at 10 days after spray. Whereas, the pesticides Wettable Sulphur 80 WP (2 g/l) and Era Safeguard (2.5 mL/L) at 10 DAS recorded less mortality of 8.30 and 17.25 per cent, respectively. Similar trends were recorded with regard to the rearing parameters of silkworms. The findings of the current study have clearly shown that the Orgomite which is a botanical formulation was proved to be the least toxic to silkworms even at 10 DAS followed by Wettable Sulphur 80 WP, Era Safeguard, Chlorfenapyr 10 SC and Azadirachtin 1 per cent at 15 DAS. Thus, Orgomite and Chlorfenapyr 10 SC were found best for the management of both mites and leaf roller with a safety period of 10 and 15 days after pesticide spray, respectively.