title: Increased Efficacy of Entomopathogenic Nematode-Insecticide Combinations Against Holotrichia oblita (Coleoptera: Scarabaeidae).
abstract: Combinations of entomopathogenic nematodes Steinernema longicaudum X-7 and Heterorhabditis bacteriophora H06 with chlorantraniliprole, diflubenzuron, and imidacloprid insecticides at different rates for the control of the white grub, Holotrichia oblita Faldermann (Coleoptera: Scarabaeidae), were evaluated both in the laboratory and in peanut fields. In the laboratory, the combinations had a synergistic or additive effect on the second-instar larvae of H. oblita and caused faster mortality than one nematode species or insecticide alone. Heterorhabditis bacteriophora-chlorantraniliprole and H. bacteriophora-imidacloprid showed synergistic effects on the larvae. When higher concentrations of the insecticides were combined with nematodes, the stronger synergistic effects were found. In peanut fields, S. longicaudum-imidacloprid, H. bacteriophora-imidacloprid, or H. bacteriophora-chlorantraniliprole also showed synergistic effects against the larvae. The three nematode-insecticide combinations produced similar percentage reductions of the grub larvae and less percentages of injured legumes, compared with the chlorpyrifos treatment. Cost-benefit analysis showed that H. bacteriophora 5.0 × 103 infective juveniles (IJs) per plant (equal to 7.5 × 108 IJ ha-1) combined with imidacloprid at the recommended concentration is a practical strategy for the practitioner to manage the white grubs in the peanut production.
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.|Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Key Laboratory of Integrated Pest Management in Agriculture, Guangdong Institute of Applied Biological Resources, Guangzhou, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: W
authors.initials: W
authors.lastname: Guo
authors.affiliation: Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Key Laboratory of Integrated Pest Management in Agriculture, Guangdong Institute of Applied Biological Resources, Guangzhou, China.
authors.forename: X
authors.initials: X
authors.lastname: Yan
authors.affiliation: Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Key Laboratory of Integrated Pest Management in Agriculture, Guangdong Institute of Applied Biological Resources, Guangzhou, China.
authors.forename: G
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Key Laboratory of Integrated Pest Management in Agriculture, Guangdong Institute of Applied Biological Resources, Guangzhou, China.
authors.forename: R
authors.initials: R
authors.lastname: Han
mesh_terms: D000818:Animals; D010367:Arachis / Q000254:growth & development; D001517:Coleoptera / Q000254:growth & development / Q000469:parasitology; D003362:Cost-Benefit Analysis; D004132:Diflubenzuron; D004305:Dose-Response Relationship, Drug; D006790:Host-Parasite Interactions; D007093:Imidazoles; D007300:Insect Control; D007306:Insecticides; D007814:Larva / Q000254:growth & development / Q000469:parasitology; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010572:Pest Control, Biological; D017168:Rhabditida / Q000502:physiology*; D062367:ortho-Aminobenzoates
chemical_list: D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D062367:ortho-Aminobenzoates; C082359:imidacloprid; C517733:chlorantranilipole; D004132:Diflubenzuron
keywords: Holotrichia oblita Faldermann; entomopathogenic nematode; insecticide; peanut; synergism