Journal of Pest Science (2020) 93, 1031-1042

Kelsey A. McCalla, Jia-Wei Tay, Ashok Mulchandani, Dong-Hwan Choe and Mark S. Hoddle (2020)
Biodegradable alginate hydrogel bait delivery system effectively controls high-density populations of Argentine ant in commercial citrus
Journal of Pest Science 93 (3), 1031-1042
Abstract: The Argentine ant, Linepithema humile (Mayr), poses a significant economic threat to citrus production in southern California. Broad-spectrum insecticide sprays provide poor ant control and present a hazard to human and environmental health. Liquid sucrose bait infused with a low concentration of insecticide is an effective alternative treatment but current approaches require considerable economic investment in plastic dispensers and continual maintenance. To produce a baiting product for control of L. humile suitable for large-scale application, a biodegradable, broadcastable alginate hydrogel for delivery of aqueous low-dose thiamethoxam sucrose bait was developed and evaluated in replicated field trials in commercial citrus groves. Ant activity was significantly reduced in hydrogel-treated trees. Peak L. humile suppression was achieved 48 h following the final hydrogel disbursement, with an estimated 91% reduction in activity from baseline estimates and a 17-fold lower activity in treated trees in comparison with untreated trees. Significant residual activity of the hydrogel treatments was recorded, with a nearly 70% reduction from pre-treatment levels persisting at least 3 weeks after the last application. We conclude that alginate hydrogels can provide excellent control of L. humile while deploying 99.99% less insecticide into orchards than commercial barrier spray treatments.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mark S. Hoddle

Research topic(s) for pests/diseases/weeds:
control - general
pheromones/attractants/traps

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Linepithema humile		U.S.A. (SW)