title: Pungent spices, ground red pepper, and synthetic capsaicin as onion fly ovipositional deterrents.
abstract: In laboratory choice experiments, the spices dill, paprika, black pepper, chili powder, ginger, and red pepper deterredDelia antiqua oviposition by 88-100%. Dose-response choice tests demonstrated that 1 mg of ground cayenne pepper (GCP) placed within 1 cm of artificial onion foliage reduced oviposition by 78%. A synthetic analog of capsaicin, the principal flavor ingredient of red peppers, deterred oviposition by 95% when present at 320 ppm in the top centimeter of sand (the ovipositional substrate). However, in no-choice conditions 10 mg GCP was not an effective deterrent. Sevana Bird Repellent and Agrigard Insect Repellent both use red pepper as a principal ingredient; at recommended field rates, neither of these materials was an effective ovipositional deterrent either in laboratory or field. Capsaicin-based materials do not appear to be candidates for onion maggot control via behavioral modification.
authors.affiliation: Department of Entomology and Pesticide Research Center, Michigan State University, 48824, East Lansing, Michigan.
authors.forename: R S
authors.initials: RS
authors.lastname: Cowles
authors.forename: J E
authors.initials: JE
authors.lastname: Keller
authors.forename: J R
authors.initials: JR
authors.lastname: Miller