IPM for onion thrips (Thrips tabaci) in onion

Onion thrips is a key pest of onion and other Allium spp. and their control is vital to the production and profitability of this crop. If thrips are not controlled, damage can routinely reduce onion bulb yields by 30-50% and such losses might be compounded if thrips infect the crop with Iris yellow spot virus (Bunyaviridae: Tospovirus), which also may reduce bulb yield Insecticide use continues to be the most important tool for onion thrips management in onion, even though this pest is notorious for developing resistance to insecticides. Most onion fields need protection against thrips for one to two months and multiple insecticide applications are made to keep infestations from damaging the crop, but there are relatively few insecticides that are highly effective. Overcoming this problem has stimulated research in three main areas: (1) discovery of novel insecticides for thrips control, (2) evaluating action thresholds to optimize insecticide use and applying insecticdes in particular sequences to maximize control while minimizing the potential for resistance development, and (3) exploring non-insecticide approaches for thrips management such as host plant resistance and cultural practices. This presentation will concentrate on these three areas by providing examples of onion thrips management in the onion cropping system in the Great Lakes region of North America.