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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Research Project #441830

Research Project: Novel Precision Technologies to Reduce Insecticide Use Targeting Aphids and Thrips in Lettuce

Location: Crop Improvement and Protection Research

Project Number: 2038-22000-020-013-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Oct 1, 2022
End Date: Jun 30, 2024

California leafy greens experience numerous insect pests, with aphids and thrips being the most problematic. Both pests threaten >$2.2 billion of lettuce production. This multi-faceted project aims to help develop and optimize new technologies to advance Integrated Pest Management strategies. We will evaluate precision insecticide applications using an automated thinner to better use insecticides in lettuce by reducing insecticide applied and improving efficacy. We will also validate drone-released natural enemies to improve biocontrol in lettuce production systems using whole-field, insectary planting, and field border releases.

Precision applications will be tested as alternatives to broadcast sprays (same per-plant application rate) or as a way to improve efficacy (higher per plant rates). The most promising materials will be used to test if a higher “per-plant” rate application extends control to reduce applications. We will test precision spray technologies to improve insecticide applications in organic systems. Three natural enemy treatments (lacewings, mites, or both, multiple releases) will be tested for control aphids and thrips. Greenhouse trials will also be conducted to examine the optimal release rates of the treatments and examine interactions with plant stage and pest pressure. We will test suppressive activity of aphid midges on aphid pests and test the potential for minute pirate bugs to control aphids and thrips and their dispersal/population dynamics when applied specifically to the insectary plant, sweet alyssum, planted as strips within lettuce. Minute pirate bugs and predatory mites will also be tested for their effectiveness to suppress thrips within border crops, such as ice plant. For field trials, pest and natural enemy populations will typically be assessed using multiple plant (lettuce/ice plant flower) collections, plant washing, and counts for pests and natural enemies. We will release predators via drone flights.