Optimizing insectary plants selection for enhancing natural enemies in bean production

Snap bean production has a value of around $362 million in the United States. Integrating habitat management practices in agroecosystems helps to restore the functional aspects of plant diversity, which are lost through crop intensification and monoculture. Insectary plants are one of many habitat management techniques that influence natural enemy (NE) populations. Insectary plants incorporated around and within crop fields can aid pest management. Flowering insectary plants attract and maintain NE by providing nectar, pollen, shelter and alternative prey. However, not all insectary plants attract NE equally. This research evaluated the potential of six insectary plants to attract NE of snap bean pests and determine which insectary plant is most beneficial. This two-year field study was done in 2023 and 2024 in South Carolina, where we intercropped selected insectary plants (alyssum, buckwheat, marigold, peppermint, sunflower, and zinnia) with snap beans. We identified the most common NE (including Orius spp., Geocoris spp., carabids, rove beetles, parasitoids, and long-legged flies) through several sampling methods in a snap bean field. Buckwheat attracted more Orius spp. than five other insectary plants during the beat sheet sampling. Therefore, incorporating buckwheat as an insectary plant in snap bean production could help farmers manage snap bean pests by attracting NE, reducing reliance on insecticide inputs, and advancing sustainable agriculture.

Key words: vegetables, habitat manipulation, biological control, insectary plants, natural enemies