Field Evaluation of a Commercial Biopesticide in Comparison with a Conventional Insecticide Against Spodoptera littoralis (Boisduval) and Scrobipalpa ocellatella (Boyd) Sugar Beet Insect Pests and their Effect on the Associated Predators

Abstract

Farag, A.A., A.H. El Kenawy and E.A. Refaei. 2023. Field Evaluation of a Commercial Biopesticide in Comparison with a Conventional Insecticide Against Spodoptera littoralis (Boisduval) and Scrobipalpa ocellatella (Boyd) Sugar Beet Insect Pests and their Effect on the Associated Predators. Arab Journal of Plant Protection, 41(3): 266-271. https://doi.org/10.22268/AJPP-041.3.266271 In this study, the insecticidal activities of one commercially available biopesticide, Biotect of B. thuringeinsis var. kurstaki, (9.4% WP, 32000 I.U./mg), and the conventional insecticide, Andros 5.7% WDG (Emamectin benzoate), against Spodoptera littoralis (Boisd.) and Scrobipalba ocellatella (Boyd) larvae and three natural enemies; Chrysoperla carnea (Steph.), Coccinella undecimpunctata L. and Scymnus interruptus (Goeze) were evaluated during 2020 and 2021 seasons in sugar beet fields at Kafr El-Sheikh Governorate, Egypt. Andros was the most effective against S. littoralis and S. ocellatella populations with reduction of 83.3% and 91% in 2020 and 82.60% and 88.96% in 2021, respectively. Whereas, Biotect had the least effect with 67.2% and 60% reduction in 2020, and 70.12% and 56.4% reduction in 2021 for S. littoralis and S. ocellatella, respectively. On the other hand, treatments had a mediocre effect during the two seasons on the predators. Andros showed the highest effect on S. interruptus larvae with a reduction of (91.0% and 98.5% reduction), on C. undecimpunctata (81.66% and 83.22% reduction) and on C. carnea (78.12% and 86.19% reduction) in 2020 and 2021 growing seasons, respectively. Andros induced the highest decline in insect numbers. From this study, it can be proposed that Biotect is a promising B. thuringeinsis product for the biocontrol of cotton leaf worm and beet moth under field conditions. Keywords: Sugar Beet, Spodotera littoralis, Scrobipalba ocellatella, Biopesticides, Predators, Field evaluation.