Evaluating the Efficacy of Insecticides in Managing the Egyptian Cotton Leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) Infestation and Their Impact on Associated Predator Populations in Sugar Beet Fields

Fergani, Yasmin A.; Fayez, Neven M.; Khalifa, Amany A.

doi:10.21608/jppp.2023.231237.1172

Evaluating the Efficacy of Insecticides in Managing the Egyptian Cotton Leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) Infestation and Their Impact on Associated Predator Populations in Sugar Beet Fields"

Document Type : Original Article

Authors

¹ Plant Protection Research Institute, Cotton Leafworm Dep. m, Bio-Pesticides Production Unit, ARC, Giza, Egypt.

² Plant Protection Research Institute, Biological Control Dep., ARC, Giza, Egypt.

10.21608/jppp.2023.231237.1172

Abstract

The cotton leafworm, Spodoptera littoralis, poses a serious threat by infesting sugar beet crops and causing significant economic losses. This study aimed to assess the effectiveness of three insecticides, the Chlorfenapyr compound, Lambda-cyhalothrin, and Methoxyfenozide - in managing early S. littoralis infestations in sugar beet fields across two growing seasons (2021-2022). The research evaluated the impact of the tested compounds on both the target pest and associated arthropod predator populations. The tested insecticides led to substantial reductions in S. littoralis larval population density. Notably, Lambda-cyhalothrin achieved a rapid 77.25% reduction within one day. Reductions of 92.33% to 97.61% occurred after seven and ten days, respectively. Cumulatively, larval population reductions recorded varied from 88% to 90% over both seasons. Assessing the impact on associated predator populations, C. Carnae (larvae), Scymnus spp, and formicides (adults) revealed unexpected declines in predator populations immediately after the Chlorfenapyr compound and Methoxyfenozide application. However, predator resilience was evident, with over 50% recovery within three days. Lambda-cyhalothrin showed a balance between pest reduction and predator preservation, though some predators were inadvertently eradicated.This study underscores the potential of tested insecticides for controlling S. littoralis in sugar beet fields. The varying effects on predator populations call for a balanced approach that considers pest management and predator preservation. Further research is needed to gauge the long-term ecological consequences and develop strategies ensuring effective pest control without disrupting predator populations. Ultimately, this study contributes valuable insights into sustainable pest management and ecosystem balance in agriculture.

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