Efficacy of afidopyropen against soybean aphid (Hemiptera: Aphididae) and toxicity to natural enemies.

BACKGROUND: Soybean aphid, Aphis glycines (Hemiptera: Aphididae), remains the most significant soybean insect pest in the North Central Region of the USA. The sustainability of reliance on only a few insecticide groups for this pest is questionable. We evaluate afidopyropen, a novel pyropene insecticide (Group 9D), for efficacy against A. glycines in field and greenhouse experiments and toxicity to common natural enemies in laboratory experiments. RESULTS: Across 4 site-years of field experiments and a greenhouse experiment, afidopyropen reduced A. glycines populations similar to commonly used broad-spectrum [i.e. lambda-cyhalothrin (Group 3A) and chlorpyrifos (Group 1B)] insecticides and potential selective insecticides [i.e. sulfoxaflor (Group 4C) and flupyradifurone (Group 4D)]. In the greenhouse, however, A. glycines mortality was delayed slightly for afidopyropen compared to the other insecticides. In laboratory experiments with natural enemies of A. glycines, afidopyropen was not toxic to adult or third instar Hippodamia convergens (Coleoptera: Coccinellidae) or adult Orius insidiosus (Hemiptera: Anthocoridae), and was only moderately toxic to Aphelinus certus (Hymenoptera: Aphelinidae). CONCLUSION: Afidopyropen is effective against A. glycines and relatively non-toxic to natural enemies, and appears to be an effective option for integrated pest management and insecticide resistance management programs for A. glycines. © 2019 Society of Chemical Industry.

Impact of Single Gene and Pyramided Aphid-Resistant Soybean on Movement and Spatial Pattern of Soybean Aphid (Hemiptera: Aphididae).

Host plant resistance may be an effective option to manage soybean aphid, Aphis glycines (Matsumura) (Hemiptera: Aphididae), an important pest on soybean (Glycine max (L.) Merr.) in the U.S. Movement of soybean aphid may be altered by the presence of resistance (i.e., Rag [Resistance to Aphis glycines]) genes in soybean and changes in movement may affect the spatial pattern of a species. This study aims to assess the effects of Rag1 and pyramided Rag1+Rag2 aphid-resistant varieties on movement of soybean aphid under laboratory conditions and to evaluate potential impacts of this movement on spatial pattern of soybean aphid under field conditions. Results from the greenhouse study showed more movement of soybean aphid on both aphid-resistant varieties than the susceptible variety when aphids were placed on unifoliate leaves and no statistically significant difference in movement between Rag1 and pyramided Rag1+Rag2 varieties. When aphids were placed on new growth, movement was greater on pyramided Rag1+Rag2 than the Rag1 and susceptible variety. However, under field conditions, the spatial patterns of soybean aphid in plots with susceptible, Rag1 or pyramided Rag1+Rag2 varieties were aggregated and did not differ among varieties in vegetative and reproductive growth stages. These results are of relevance because they suggest that aspects of soybean aphid management that may be sensitive to changes in spatial pattern of the pest (e.g., natural enemy efficacy and sampling plans) may not be impacted by implementation of varieties with these resistance genes for host plant resistance.