title: Toxicity of botanical formulations to nursery-infesting white grubs (Coleoptera: Scarabaeidae).
abstract: The toxicity of eight botanically based biopesticides was evaluated against third instars of the scarab larvae (Coleoptera: Scarabaeidae) Popillia japonica Newman, Rhizotrogus majalis (Razoumowsky), Anomala orientalis Waterhouse, and Cyclocephala borealis Arrow. Soil dip bioassays were used to obtain concentration-mortality data 7 d after treatment of larvae, leading to the calculation of LC50 and LC90 values. A wide range in LC50 and LC90 values were exhibited among the formulations. The product Armorex was one of the most active formulations against P. japonica (LC50 = 0.42 ml/liter), R. majalis (LC50 = 0.48 ml/liter), A. orientalis (LC50 = 0.39 ml/liter), and C. borealis (LC50 = 0.49 ml/liter). Armorex is composed of extracts from diverse botanical sources, including 84.5% sesame oil, 2.0% garlic oil, 2.0% clove oil, 1.0% rosemary oil, and 0.5% white pepper extracts. The product Azatin, composed of 3% azadirachtin, also exhibited high toxicity to P. japonica (LC50 = 1.13 ml/liter), R. majalis (LC50 = 0.81 ml/liter), and A. orientalis (LC50 = 1.87 ml/liter). Veggie Pharm is composed of extracts from diverse sources, but this product showed the lowest toxicity to P. japonica (LC50 = 35.19 ml/liter), R. majalis (LC50 = 62.10 ml/liter), A. orientalis (LC50 = 43.76 ml/liter), and C. borealis (LC50 = 50.24 ml/liter). These results document the potential for botanical formulations to control white grubs, but blending extracts from diverse botanical sources does not ensure enhanced biological activity.
authors.affiliation: Application Technology Research Unit, Horticultural Insects Research Laboratory, USDA-ARS, 1680 Madison Avenue, Wooster, OH 44691, USA. christopher.ranger@ars.usda.gov
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Ranger
authors.forename: Michael E
authors.initials: ME
authors.lastname: Reding
authors.forename: Jason B
authors.initials: JB
authors.lastname: Oliver
authors.forename: James J
authors.initials: JJ
authors.lastname: Moyseenko
authors.forename: Nadeer N
authors.initials: NN
authors.lastname: Youssef
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000187:drug effects*; D005989:Glycerides / Q000494:pharmacology*; D007302:Insect Repellents / Q000494:pharmacology*; D007814:Larva; D010938:Plant Oils / Q000494:pharmacology*; D018517:Plant Roots / Q000469:parasitology*; D013729:Terpenes / Q000494:pharmacology*; D018675:Toxicity Tests
chemical_list: D005989:Glycerides; D007302:Insect Repellents; D010938:Plant Oils; D013729:Terpenes; C002443:neem oil