The development of the asparagus miner (Ophiomyia simplex Loew; Diptera: Agromyzidae) in temperate zones: a degree-day model.

BACKGROUND The asparagus miner is a putative vector of Fusarium spp., which have been implicated in globally declining asparagus production. Growers currently apply broad-spectrum insecticides for the asparagus miner, but lack management guidelines for adequately controlling the pest. Our aims were (1) to determine the lower developmental threshold of the asparagus miner, (2) develop and validate a degree-day model describing its phenology, and (3) create a developmental time budget for the asparagus miner to help guide growers' management decisions. RESULTS We found that the lower developmental threshold for the asparagus miner was 12.1 °C, and that the phenology of the asparagus miner could be reliably predicted over the course of a two-year study. Predictions from the model match well with previously published information on the bionomics of the asparagus miner, but fit better for sampling data collected from the midwestern and eastern United States than for the United Kingdom. The life cycle of the asparagus miner likely requires between 1500 and 2000 degree-days to complete; the longest developmental time requirement was for the pupal stagen CONCLUSION This study provides tools for the targeted management of the asparagus miner by offering a degree-day model that may be used to predict its life stages in the north-eastern United States.