Pheromone-Assisted Techniques to Improve the Efficacy of Insecticide Sprays Against <I>Linepithema humile</I> (Hymenoptera: Formicidae)

Abstract

Outdoor residual sprays are among the most common methods for targeting pestiferous ants in urban pest management programs. If impervious surfaces such as concrete are treated with these insecticides, the active ingredients can be washed from the surface by rain or irrigation. As a result, residual sprays with fipronil and pyrethroids are found in urban waterways and aquatic sediments. Given the amount of insecticides applied to urban settings for ant control and their possible impact on urban waterways, the development of alternative strategies is critical to decrease the overall amounts of insecticides applied, while still achieving effective control of target ant species. Herein we report a "pheromone-assisted technique" as an economically viable approach to maximize the efficacy of conventional sprays targeting the Argentine ant. By applying insecticide sprays supplemented with an attractive pheromone compound, (Z)-9-hexadecenal, Argentine ants were diverted from nearby trails and nest entrances and subsequently exposed to insecticide residues. Laboratory experiments with fipronil and bifenthrin sprays indicated that the overall kill of the insecticides on Argentine ant colonies was significantly improved (57-142% increase) by incorporating (Z)-9-hexadecenal in the insecticide sprays. This technique, once it is successfully implemented in practical pest management programs, has the potential of providing maximum control efficacy with reduced amount of insecticides applied in the environment.

Efficacy of Trunk Trap Nets and Insecticides Applied Alone and in Combination for Control of Tree-of-heaven Root Weevil Eucryptorrhynchus scrobiculatus in Ailanthus altissima Plantations

“…The application of chemical insecticide sprays could rapidly suppress insect pest population density. Chemical insecticides and other methods (e.g., microbial control agents, attractants, and classical biological control agents) have additive or synergistic effects on insect pests [24][25][26][27][28][29][30][31] and can be conducive to reducing insecticide use and costs [32,33]. However, no additive or synergistic effects on TRW populations and tree health, and the survival between TTN and insecticides, were found in this study.…”

Larval Pheromone Disrupts Pre-Excavation Aggregation of Cactoblastis cactorum (Lepidoptera: Pyralidae) Neonates Precipitating Colony Collapse

“…In another study, Sunamura et al (2011) showed that combining insecticide baits with trail pheromone dispensers resulted in better control of ants than did baits alone. Choe et al (2014) obtained similar results by mixing trail pheromone with an insecticide. Studies by Westermann et al (2014) suggested that long term disruption of foraging behavior of the Argentine ant with a synthetic trail pheromone might reduce their competitive ability, leading to collapse of populations in favor of less harmful, indigenous species.…”

Development of a Pheromone-Assisted Baiting Technique for Argentine Ants (Hymenoptera: Formicidae)

“…Furthermore, higher foraging activity for the pheromone-treated gel bait translates to higher final mortality. Because (Z)-9-hexadecenal is not insecticidal (Choe et al 2014), the increase in the final mortality found in the pheromone-treated gel bait is attributed to the increasing number of Argentine ant foragers that are discovering and consuming the gel bait within the fixed amount of time. The consumption data from the field study also indicate that Argentine ants consistently consume more gel bait when it is treated with (Z)-9-hexadecenal (Fig.…”

“…Several studies have explored the possibility of using a synthetic trail-following pheromone to develop practical management strategies for the Argentine ant. Choe et al (2014) reported that the addition of (Z)-9-hexadecenal, a putative trail pheromone component of Argentine ants, into insecticide sprays improved the sprays efficacy because (Z)-9-hexadecenal attracts worker ants from nearby locations to the insecticide spray deposits. Greenberg and Klotz (2000) showed that (Z)-9-hexadecenal, when mixed with a sugar solution, increases Argentine ant consumption.…”