A drone releases green lacewing eggs and predatory mites over a Salinas Valley lettuce field. Researchers say such aerial applications show promise for controlling aphids and other pests.
Beneficial bugs from drones help manage pests in lettuce
By Caitlin Fillmore Researchers, farmers and technology entrepreneurs are experimenting with drones to drop thousands of beneficial in-
founder of the Salinas agriculture tech- nology firm Parabug, Del-Pozo concluded that “our results could be interpreted as preliminary evidence that drone-released lacewings could reduce aphid densities when compared to untreated plots.” The study also noted that drone de- ployments of beneficial insects could be a useful complement to organic-certified insecticides on organic lettuce to help save on labor costs. “Traditionally, the cost of labor has lim- ited the use of beneficials in the lettuce production system, but the use of drones for these releases may make this strategy more attractive,” the report said. In an interview, Morgan said drone use in agriculture “presents unparal- leled opportunities for enhancing effi- ciency and precision.” He noted that drones already assist in plant population counts by reducing plant loss during cultivation. He said he sees opportunities to use drones to help calculate irrigation uniformity and apply pesticides and nutrients while boosting worker safety. “The sky is the limit, and we need inno- vative thinkers and engineers to develop drone-based tools that meet the evolving needs of growers,” Morgan said. The drone and lacewing egg exper- iment inspired further research from Addie Abrams, a doctoral candidate and researcher at UC Davis. Abrams is expand- ing the lacewing study, adding repeated releases of green lacewing eggs at different phases in the lettuce growing cycle. “There is the potential here to provide an alternative to chemical sprays that still lets growers respond quickly to changes in pest pressure in the field,” Abrams said. Abrams’ study adds drone releases of predatory Amblyseius cucumeris mites and combined releases of the mites with green lacewing eggs to suppress western flower thrips.
sects over farm fields as eco-friendly com- batants against de- structive insect pests. In the Salinas Valley, thrips in recent years have
SCIENCE & TECHNOLOGY
spread impatiens necrotic spot virus in let- tuce fields, causing significant losses. That and other pest concerns inspired quests for innovative solutions. Experiments led by former University of California Cooperative Extension entomol- ogy advisor Alejandro Del Pozo-Valdivia and the UC Davis Fi-VE Bug IPM Lab first analyzed a single drone release of green lacewing eggs to combat lettuce aphids, which transmit the lettuce mosaic virus. It worked: Del-Pozo Valdivia’s first at- tempt employing a drone to spit out green lacewing eggs a single time over an organ- ic lettuce field helped curb aphid popu- lations in the limited conditions studied. Ian Grettenberger, an entomology spe- cialist at UC Davis, said the trial represent- ed one of many steps towards developing new technologies and practices to support sustainable pest management goals. “We are looking at the whole gamut for integrated pest management options,” Grettenberger said. “It’s a ‘many small hammers’ approach.” According to the trial findings, which were published in the Sept. 15, 2021 Journal of Economic Entomology, aphid populations were reduced after lacewing eggs were released from drones at a rate of 74,131 eggs per hectare, or more than 183,000 per acre, and organic-certified in- secticides were used. Along with fellow journal authors Eric Morgan, vice president of environmen- tal science for Salinas-based Braga Fresh Family Farms, and Chandler Bennet,
See DRONES, Page 9
July 24, 2024 Ag Alert 3
Powered by FlippingBook