Influence of some insecticide sequences on the injurious insect- pests of cotton plants

Abstract

Background: Cotton growers in Egypt have experienced severe economic loss from cotton bollworms, especially the pink bollworm, Pectinophora gossypiella (Saund.), and spiny bollworm, Earias insulana (Boisd.), so a field experiment was carried out to determine efficiency of eight insecticides in their seven sequence programs to evaluate the best solution for cotton bollworms problems, during two successive seasons. Results: The highest reduction percentages are effective sequences 7 and 5 (gave about 90% infestation reduction) were started and mediated with new insecticides, and when started and mediated with spinosad, or with cypermethrin, sequences 2 and 3 (gave about 86%) respectively, also, the repetition of the same insecticide twice in a regimen might increase, might decrease, or has no effect on the insecticide efficiency against cotton bollworms. The tested sequence programs showed high protection for green bolls with protection percentages ranged from 66.1 and 67.2% (sequence 1) to 92.6 and 94.1% (sequence 7) during two seasons respectively. On the other hand, the superiority in yield loss reduction can arrange in the following descending order: sequences 7, 5, 2, 3, 6, 4, and 1 respectively. Conclusions: From this study, it can be concluded that the importance of sequence insecticide programs included new groups of insecticides to directing tactics to fight against resistance development and used this sequence programs to restore susceptibility for conventional insecticides. This study devoted to obtaining the optimum regimen of insecticides that give low reduction of cotton bollworms' infestation and high cotton yield.

Effect of planting dates and recommended insecticides application on Earias insulana (Boisd.) and its associated predators in cotton field in Egypt

“…The effect of recommended insecticides application against the spiny bollworm in this study was similar to that observed by Ansari and Kumar (1988), Saad et al . (2015) and Ismail (2019). The use of chlorpyrifos and lambda-cyhalothrin insecticides resulted in a high reduction in the E. insulana population.…”

Efficacy of Spinosad 48SC on the Management of Cotton Bollworms Diparopsis castanea (Hubner) and Herlicoverpa amigera (Hampson) in Zimbabwe

“…It is the most damaging pest of cotton because it attacks the fruiting parts of the plant, [1]. The damage caused by bollworms as they feed on cotton buds, flowers and bolls results in 20-60% yield and quality loss, [2]. Three bollworm species cause main damage on cotton in India: the pink bollworm (Pectinophora gossypiella), the spotted bollworm (Earias vitella), and the American bollworm (Helicoverpa armigera), [3].…”