Abstract
Disruption of foraging using oversupply of ant trail pheromones is a novel pest management application under investigation. It presents an opportunity to investigate the interaction of sensory modalities by removal of one of the modes. Superficially similar to sex pheromone-based mating disruption in moths, ant trail pheromone disruption lacks an equivalent mechanistic understanding of how the ants respond to an oversupply of their trail pheromone. Since significant compromise of one sensory modality essential for trail following (chemotaxis) has been demonstrated, we hypothesised that other sensory modalities such as thigmotaxis could act to reduce the impact on olfactory disruption of foraging behaviour. To test this, we provided a physical stimulus of thread to aid trailing by Argentine ants otherwise under disruptive pheromone concentrations. Trail following success was higher using a physical cue. While trail integrity reduced under continuous over-supply of trail pheromone delivered directly on the thread, provision of a physical cue in the form of thread slightly improved trail following and mediated trail disruption from high concentrations upwind. Our results indicate that ants are able to use physical structures to reduce but not eliminate the effects of trail pheromone disruption.
Highlights
The Argentine ant, Linepithema humile (Mayr) is widely distributed across the globe[1], with populations in Europe[2], California[3], Australia[4], Japan[5] and New Zealand[6, 7]
When pheromone-dipped thread of different concentrations was offered to the ants to test trail following behaviour in the presence of synthetic trail pheromone, it was observed that trail integrity was high (r2 > 0.90) over three orders of magnitude of trail strength
At a high loading of pheromone on the thread (>3.74 pg/cm), trail integrity (r2 = 0.78) was already at a threshold at which ants would have a reduced ability to successfully recruit to a food source (Fig. 2)
Summary
The Argentine ant, Linepithema humile (Mayr) is widely distributed across the globe[1], with populations in Europe[2], California[3], Australia[4], Japan[5] and New Zealand[6, 7]. The mechanism, concentrations, and factors affecting trail following in Argentine ants were examined by van Vorhis Key et al.[31] and van Vorhis Key and Baker[32,33,34], based on the earlier work of Cavill et al.[35] who made extracts from Argentine ant ventral glands. We followed the work by Cavill et al.[35] and Van Vorhis Key and Baker[33] and used the methods of Suckling et al.[23] to digitise tracks in order to compare the trail following behaviour to gaster extracts and synthetic (Z)9-hexadecenal, and trail following ability under pheromone disruption with a countervailing physical cue. We applied the trail integrity statistic (r2), derived from linear regression from digitised trails
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
