No specialist pheromone‐ignoring ants in Lasius niger. (12th December 2020)

• Record Type: Journal Article
• Authors: Koch, Alexandra; Czaczkes, Tomer J.
• Is Part Of: Ecological entomology. Volume 46:Number 3(2021)
• Page Start: 677
• Page End: 680
• Publication Date: 2020-12-12
• Subjects: Behavioural castes -- individual differences -- pheromone trails -- scouts -- social information; Insects -- Ecology -- Periodicals; Entomology -- Periodicals; 595.7
• DOI: 10.1111/een.12995
• Languages: English
• ISSNs: 0307-6946

Abstract

Abstract : In insect societies, the balance between exploitation of known resources and exploration of new ones is important to ensure sufficient resources. Mass recruiting ants, such as Lasius niger, use pheromone trails to recruit nestmates to a newly discovered food source. Pheromone following, however, shows characteristic non‐following (lapse) rates among different species, with ∼20% of L. niger foragers ignoring pheromone. These characteristic lapse rates might simply be 'noise', or they might indicate a subset of specialised explorative foragers, a scouting caste, that consistently ignores pheromone in order to explore. Here we show pheromone ignoring is not a repeatable behaviour in L. niger foragers – ants who did not follow a trail were no more likely to ignore it again an hour later than ants which did follow it. Our findings suggest that there is no subset of specialised pheromone‐ignoring L. niger foragers. This may be due to their moderate colony size and strong reliance on individual memories: species with larger colony sizes or a weaker reliance on private information (i.e. memory) may have specialist non‐followers. Our work raises the question: what is a scout ant? We encourage future research to investigate the presence of a scouting caste in other ant species using our straightforward methodology, as a social information‐ignoring caste may be rarer than expected. Abstract : Many social insects have behavioural castes which perform a specialist role in the colony We test whether Lasius niger ants have a specialist 'pheromone ignorer' scout caste Ants which did not follow pheromones in one assay were not more likely to ignore pheromone in a second assay. No specialist 'pheromone ignorer' caste was found.