Potency of certain insecticides and their effect on some biochemical aspects using semi-field technique in Spodoptera littoralis
Hanan S Abd-El-Aziz, Mohamed Fathy Abdel Aziz
The comparative potency of tested insecticides; namely Lamba Val, (Lambda-cyhalothrin), Acetathrin El-Nasr (Acetamprid + Lambda-cyhalothrin) and Tracer 24 % (spinosad) from different chemical groups was evaluated to confirm the most effectual insecticide against Spodoptera littoralis larvae. The semi-field applications, showed significant difference effect between 2nd and 4th intstars during tested days. The 2nd instar larvae were more susceptible than 4th instar larvae from the first day of application and gradually increased to reach its maximum effective day after 7 days in case of testing the 2nd instar larvae, while the maximum mortality reached after 10 days in case of 4th instar larvae with all tested insecticides. The most effective insecticide was the mixture of Acetamprid and Lambda cyhalothrin followed by Lambda cyhalothrin. Spinosad was the slowest effectiveness in controlling S. littoralis, comparing with Acetamprid + Lambda cyhalothrin and Lambda cyhalothrin. Biochemical studies revealed that both LC50 and LC25 had highly significant reduction in total protein content and alkaline phosphatase activity in the 4th instar larvae with all tested compounds compare with control. In the same trend, the tested insecticides, were more effective on Na+ and Ca++ by their significant reduction effect, particularly Na+ with LC50’s and not significant between each other. On the other hand, no significant effect on K+ was noticed.
Hanan S Abd-El-Aziz, Mohamed Fathy Abdel Aziz. Potency of certain insecticides and their effect on some biochemical aspects using semi-field technique in Spodoptera littoralis. International Journal of Entomology Research, Volume 6, Issue 2, 2021, Pages 235-242