Response of seedcorn maggot (Diptera: Anthomyiidae) to seed-attractant combinations

Insects use volatile organic compounds (VOCs) as environmental cues for resource-searching. Volatile cues provide information that can attract pollinators and natural enemies or repel crop pests. Naturally occurring VOCs are valuable tools for controlling and monitoring pests as part of integrative pest management strategies. However, their effectiveness as monitoring tools depends on the surrounding context, emphasizing the importance of evaluating their performance within the specific conditions in which they will be deployed. Delia platura (Meigen), or seedcorn maggot, is a globally distributed pest, often feeding on seeds of legumes, allium, and cereal grains. Adults of this pest rely on olfaction when searching for oviposition sites. To determine which cues are more attractive for D. platura, and if the attraction to certain cues depends on the surrounding crop context, a 2-factorial blocked experiment was conducted to test the individual and combined effects of previously reported attractants (silage alfalfa, fresh alfalfa, manure, fish meal, bone meal, soil, a commercially available attractant and control soils) and at-risk crop species (field corn, soybean, and snap bean) on adult response. There were differences between attractants and seed types but no interactions. Traps containing silage alfalfa attracted more flies than the controls and the commercially available attractant. Traps containing corn attracted more flies than those containing soybean. These results indicate that D. platura uses volatile cues to differentiate among attractant sources and seed types, and that future management practices could use the same attractant across the 3 crop systems.