Vol. 9, Special Issue 1, Part L (2025)

The present investigation ‘Efficacy of some Chemosterilants on Helicoverpa armigera (Hubner) in laboratory’ was conducted during 2017- 2018 in Insect Toxicology Laboratory of Department of Agricultural Entomology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. The study was undertaken to know the effects of Chemosterilants on biological parameters and reproductive capabilities of H. armigera (Hub.). Two Chemosterilants and two botanicals viz., TEPA, Thiourea and Azadirachtin 300 ppm, NSKE 3 % were used against third instar larvae of H. armigera (Hub.).

The results on the effect of different treatments on larval weight and larval period of H. armigera (Hub.) revealed that the lowest larval weight was found in Azadirachtin @ 0.3 % and lowest larval period was found in TEPA @ 5% followed by Thiourea @ 0.10 %. The effect of different treatments on pupal weight and pupal period H. armigera (Hub.) revealed that the lowest pupal weight was found in Azadirachtin @ 0.3 % treatment, followed by Azadirachtin @ 0.1 %, Thiourea @ 0.01 % and Thiourea @ 0.10 % and highest pupal period was found in TEPA @ 5 %.

The highest percentages of malformed pupae were observed in TEPA @ 5 %. It was followed by Azadirachtin @ 0.10 %, NSKE @ 3 %, TEPA @ 2.5 %, TEPA @ 1.25 % and Azadirachtin @ 0.1 %. The lowest adult emergence was found in TEPA @ 5%, followed by Azadirachtin @ 0.1 %, TEPA @ 2.5 %, TEPA @ 1.25 %, Thiourea @ 0.10 %, Azadirachtin @ 0.3 % and NSKE @ 3 %. The highest adult malformation was found in Thiourea @ 0.10 %, followed by Azadirachtin @ 0.01 %, TEPA @ 2.5 %, TEPA @ 1.25 % and TEPA @ 5 %, however rest of other treatments superior over control.

The effect of different treatments on fecundity of H. armigera. Lowest fecundity was recorded in TEPA@ 5%, followed by TEPA @ 2.5% TEPA @ 1.25 %. The lowest male longevity was found in treatment TEPA @ 5 %, followed by Thiourea @ 0.10 % and TEPA @ 2.5 %.

The results on the effect of different treatments on egg hatchability of H. armigera showed that the lowest egg hatchability was found in TEPA @ 5 %.