Foraging Distance of the Argentine Ant in California Vineyards

Abstract

Argentine ants, Linepithema humile (Mayr) (Hymenoptera: Formicidae), form mutualisms with hemipteran pests in crop systems. In vineyards, they feed on honeydew produced by mealybugs and soft scales, which they tend and protect from natural enemies. Few options for controlling Argentine ants are available; one of the more effective approaches is to use liquid baits containing a low dose of an insecticide. Knowledge of ant foraging patterns is required to estimate how many bait stations to deploy per unit area. To measure how far ants move liquid bait in vineyards, we placed bait stations containing sugar water and a protein marker in plots for 6 d, and then collected ants along transects extending away from bait stations. The ants moved an average of 16.08 m and 12.21 m from bait stations in the first and second years of the study, respectively. Marked ants were found up to 63 m from bait stations; however, proportions of marked ants decreased exponentially as distance from the bait station increased. Results indicate that Argentine ants generally forage at distances <36 m in California vineyards, thus suggesting that insecticide bait stations must be deployed at intervals of 36 m or less to control ants. We found no effect of insecticide on distances that ants moved the liquid bait, but this may have been because bait station densities were too low to affect the high numbers of Argentine ants that were present at the study sites.

Uneven substrates constrain walking speed in ants through modulation of stride frequency more than stride length

“…This finding directly links worker-level walking performance to colony-level foraging behaviour and supports the hypothesis that uneven substrates impact colony-level performance. Surprisingly, the selection of 'easier' paths is observed even over relatively short walking distances (12 cm) compared to Argentine ant foraging distances in the field (on average greater than 12 m and up to 63 m) [44]. More generally, this sensitivity to substrate structure may provide a critical link between the biomechanical challenges of locomotion on natural substrates and habitat preference in different species.…”

Rough substrates constrain walking speed in ants through modulation of stride frequency and not stride length

“…This finding directly links worker-level walking performance to colony-level foraging behavior, and supports the hypothesis that rough substrates impact colony-level performance. Surprisingly, the selection of "easier" paths is observed even over relatively short walking distances (12 cm) compared to Argentine ant foraging distances in the field (on average >12 m and up to 63 m) [35]. More generally, this sensitivity to substrate structure may provide a critical link between the biomechanical challenges of locomotion on natural substrates and habitat preference in different species.…”

Hydrogels: From Controlled Release to a New Bait Delivery for Insect Pest Management

“…Baits exploit the recruitment and food sharing behavior of ants so that the AI can be spread to all the colony members, including the queens via trophallaxis ( Oi et al 2000 ; Rust et al 2004 ; Suiter et al 2006 ; Tay and Lee 2014 , 2015b ; Tay et al 2014 ; Welzel and Choe 2016 ). The current liquid baiting method requires bait stations to store and dispense the sucrose bait ( Hogg et al 2018 ). Although numerous new bait stations designs have been developed and registered in the market, bait stations are typically expensive and labor-intensive to maintain ( Nelson and Daane 2007 , Rust et al 2015 , Cooper et al 2019 ).…”