Onion thrips, (Thrips tabaci), is a significant economic pest of onion in the Northeast. Onion thrips reduce bulb yields through feeding injury on leaf tissue and the transmission of destructive plant pathogens. Thrips feeding damage can have immense economic consequences as it can cause reductions in bulb weight of more than 50%, which threatens the viability of onion production in the region. Growers predominantly rely on insecticide applications to control onion thrips populations, with action thresholds based on the mean number of thrips per leaf. These programs have been used successfully to provide season-long thrips control, but with 1-5 fewer insecticide applications compared with a weekly spray program. While the adoption of this action-threshold based program has reduced costs, control decisions depend upon significant sampling efforts, which can be a barrier to adoption. To address this concern, spatially-optimized sequential sampling plans for onion thrips will be developed to provide rapid estimates of pest densities and abundance to determine the most appropriate control decision, time of application, and effect required to minimize pest populations thereby increasing crop yield. Information generated from this project will enable growers to assess the risk of onion thrips infestations rapidly with statistical precision and reduce insecticide applications that are frequently overused and can have negative environmental consequences. When adopted, this sampling plan will also result in significant reductions in sampling time needed to make control decisions, thereby increasing efficiency, sustainability, cost savings, and grower adoption.
