Biological control potential in high tunnel vegetable production

The interest in sustainability and learning where our food comes from has invigorated the need for fresh local food production. In Illinois, local produce production is limited by climate and high tunnels allow vegetable growers to extend their growing season thus allowing more people to access local produce. High tunnel production may increase in the coming years as the demand for local food increases. High tunnels have unique pest pressures, with a hybrid of open field and greenhouse pests. Many of the common greenhouse pests, aphids, thrips, and mites, are difficult to control through conventional means leaving high tunnel growers looking for more sustainable, non-chemical means of insect and mite control. Biological control by insect predators may be a viable solution for these growers achievable through either releases of commercially available natural enemies or conservation of natural enemies present in the system. We released commercially available generalist predators and monitored the effect on pests in high tunnels in tomato and pepper production through yellow sticky cards, plant counts and molecular gut content analysis. Our results showed that several pest groups were decreased with natural enemy release, while thrips numbers were higher. Additionally, a diverse suite of predators was found to be consuming pests in our tunnels. In future, we will focus on other thrips control techniques and focus on the other pest groups for biological control.