Submitted to: NCB-ESA North Central Branch Entomological Society of America
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2009
Publication Date: 3/25/2009
Citation: Ranger, C.M., Reding, M.E., Oliver, J.B., Moyseenko, J.J., Youseef, N.N. 2009. Toxicity of botanical formulations to nursery-infesting white grubs (Coleoptera: Scarabaeidae). NCB-ESA North Central Branch Entomological Society of America.Available: http://www.esancb.org/files/ampdf/am2008.pdf Interpretive Summary:
Technical Abstract: The toxicity of eight commercially-available botanical formulations were evaluated against 3rd instars of the nursery-infesting white grubs (Coleoptera: Scarabaeidae) Popillia japonica Newman, Exomala orientalis (Waterhouse), Rhizotrogus majalis (Razoumowsky), and Cyclocephala borealis Arrow. In vitro soil dip bioassays were used to obtain dose-mortality data 7 d after treatment of larvae, leading to the calculation of LC50 and LC90 values for each combination of product and white grub spp. A wide range in LC50 and LC90 values were exhibited among the formulations, but the product Armorex was the most consistently active formulation against P. japonica (LC50 = 0.42 ml/l), R. majalis (LC50 = 0.48 ml/l), E. orientalis (LC50 = 0.39 ml/l), and C. borealis (LC50 = 0.49 ml/l). Armorex is comprised of metabolites from diverse botanical sources, including sesame oil, garlic oil, rosemary oil, white pepper extracts, and the individual metabolite eugenol. The product Azatin, comprised of 3% azadirachtin, also exhibited high toxicity to P. japonica (LC50 = 1.13 ml/l), R. majalis (LC50 = 0.81 ml/l), and E. orientalis (LC50 = 1.87 ml/l). The product Veggie Pharm is comprised of extracts from diverse sources, but showed the lowest toxicity to P. japonica (LC50 = 35.19 ml/l), R. majalis (LC50 = 62.10 ml/l), E. orientalis (LC50 = 43.76 ml/l), and C. borealis (LC50 = 50.24 ml/l). These results document the potential for bioinsecticides to control soil-dwelling white grubs; however, the large variation in product efficacy indicates composition of the botanical formulations is critical for biological activity.