European earwig (Dermaptera: Forficulidae) transportation workshops for orchard pest biocontrol

Abstract

European earwigs are predators of woolly apple aphid (Eriosoma lanigerum [Hausmann]) (Hemiptera: Aphididae) and pear psylla (Cacopsylla pyricola [Foerster]) (Hemiptera: Psyllidae), 2 pests that are difficult to control with insecticides. Standard orchard pesticide programs in the Pacific Northwest United States region can suppress European earwig populations to undetectable levels, and low dispersal precludes substantial natural European earwig population growth within a season when the resident population is low. Therefore, workshops were conducted to teach orchardists how to transport European earwigs (Forficula dentata F. = F. auricularia L. sensu lato) (Dermaptera: Forficulidae) for biocontrol of apple and pear pests. The workshops emphasized European earwig inoculation alongside transition to integrated spray programs. Most workshop attendees reported intent to conduct their own collection and transportation, but few did the next year. Calculations of materials and labor costs indicate the per acre expenses of European earwig transportation should not be a major barrier to adoption, but the technique requires special planning and training, and it is only useful in specific circumstances. Transportation guidelines, cost estimates, and survey data in this article could be used by researchers and managers to plan more effective European earwig research and applications.