Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/21/2005
Publication Date: 12/1/2005
Citation: Lacey, L.A., Neven, L.G., Headrick, H.L., Fritts, Jr, R. 2005. Factors affecting entomopathogenic nematodes (Steinernematidae) for the control of overwintering codling moth (Lepidopetera: Tortricidae) in fruit bins. Journal of Economic Entomology. 98(6):1863-1869. Interpretive Summary: Fruit bins infested with overwintering codling moth larvae are a potential source of reinfestation of orchards and may jeopardize the success of mating disruption programs and other control strategies. Researchers at the USDA-ARS, Yakima Agricultural Research Laboratory conducted studies to develop and evaluate insect-specific nematodes for control of cocooned larvae in fruit bins. It was found that infective stages of two species of nematodes were highly effective at controlling cocooned larvae in fruit bins and formulation of the nematodes to improve penetration of the crevices in the bins and to retard drying of the nematodes improved their activity. These findings indicate that insect-specific nematodes could provide a non-chemical means of control that could be applied at the time bins are submerged in dump tanks at the packing house for flotation of fruit.
Technical Abstract: Diapausing codling moth larvae in miniature fruit bins were highly susceptible to infective juveniles of the insect specific nematodes, Steinernema carpocapsae and S. feltiae in a series of experiments. Overwintering larvae were significantly more susceptible to infective juveniles of S. feltiae than were pupae. Immersion of bins in suspensions of nematodes ranging from 10 to 50 infective juveniles/ml of water in a commercial packing line resulted in mortality in cocooned codling moth larvae of 45-87% and 56-85% for S. feltiae and S. carpocapsae, respectively. Use of adjuvants to increase efficacy of S. feltiae in fruit bins by increasing penetration of hibernacula and by slowing desiccation resulted in improved activity under certain humidity conditions. Treatment of bins with IJs using a drencher used to cool fruit also provided control of cocooned larvae.