Naturally Occurring Predators of Asparagus Miner (Diptera: Agromyzidae)

Ari S. Grode, Adam J. Ingrao, Jason Schmidt, and Zsofia Szendrei
Department of Entomology, Michigan State University

Presented at the All Scientist Meeting (2015-04-15 to 2015-04-16 )

Asparagus miner (AM), Ophiomyia simplex Loew (Diptera: Agromyzidae) is a major pest in Michigan asparagus production and has been identified as a putative vector for Fusarium spp. of pathogenic fungi. Although prior research has documented parasitoids of AM, the naturally occurring predators of AM are unknown. The goal of this research was to identify third trophic level members for potential conservation biological control efforts for AM and characterize their spatial distribution in the fields. Predatory arthropods and AM were collected from 20 commercial asparagus farms in Oceana County, Michigan over a 7-week post-harvest period. Distribution of AM predators and AM were quantified at transects 10m away from the field edge in the border habitat, at the field edge, and 20m into the asparagus field. Molecular gut content analysis using recently developed AM specific primers was used to identify predators of AM. Of the 1395 predators caught and identified in 2014, 47 spiders and 40 insects screened positive for AM (6.24% positive). All together 23 unique AM predator taxa were identified; out of these, 13 were spider groups and 10 insect families. Four abundant AM predator families that screened positive were Linyphiidae (Araneae), Hahniidae (Araneae), Staphylinidae (Coleoptera) and Carabidae (Coleoptera). Results of this research indicate that AM predators are in significantly higher abundances outside the field in the border habitat, while AM had significantly higher abundances at the field edge. Overall, our research has identified predators as candidates for conservation biological control of AM.