Gnamptogenys menadensis

Gnamptogenys menadensis is an arboreal nester that forages opportunistically almost exclusively on vegetation, sometimes recruiting others to participate in prey retrieval. The three-dimensional characteristics of vegetation suggest that functions describing recruitment decision thresholds or the pattern of recruitment in arboreal species may differ from those predicted by optimal foraging theory. To examine the effects of prey abundance and distance on recruitment dynamics of G. menadensis, we baited nests with 1, 5 or between 20-40 termites near or far from the entrance and observed the ensuing behaviors. G. menadensis recruited others when encountering multiple termites regardless of the termite pile's distance from the nest, although a few individuals remained at the site and defended the resource. The pattern of arrivals at the site indicates that the majority and sometimes all arrivals were recruited from the branch trails. In combination, these results suggest that the architecture of the foraging habitat, which limits available return routes to the nest and thus increases encounter probabilities with potential recruits, shaped the process of information transfer and generated a collective pattern of foraging and prey retrieval. This work was carried out in the Laboratory of Entomology at the Katholieke Universiteit Leuven, headed by Dr. Johan Billen.

Classification: Formicidae: Ectatomminae: Ectatommini: Gnamptogenys (new subfamily per Bolton 2003)

Reference: Johnson CA, Lommelen E, Allard D & Gobin B. (2003) The emergence of collective foraging in the arboreal Gnamptogenys menadensis. Naturwissenschaften, 90:332-336.