Open AccessAssociation between the A frican lycaenid, A nthene usamba , and an obligate acacia ant, C rematogaster mimosae
Author(s) -
Martins Dino J.,
Collins Steve C.,
Congdon Colin,
Pierce Naomi E.
Publication year - 2013
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1111/bij.12037
Subject(s) - biology , obligate , mutualism (biology) , acacia , myrmecophily , larva , botany , nectar , hymenoptera , ant , host (biology) , myrmecophyte , zoology , ecology , pollen
The A frican lycaenid butterfly, A nthene usamba , is an obligate myrmecophile of the acacia ant, C rematogaster mimosae . Female butterflies use the presence of C . mimosae as an oviposition cue. The eggs are laid on the foliage and young branches of the host plant, A cacia drepanolobium . Larvae shelter in the swollen thorns (domatia) of the host tree, where they live in close association with the acacia ants, and each larva occupies a domatium singly. A nthene usamba are tended by ants that feed from the dorsal nectary organ at regular intervals. Larvae also possess tentacle organs flanking the dorsal nectary organ and appear to signal to ants by everting these structures. Larvae were observed to spend most of their time within the domatia. Stable isotope analysis of matched host plant–ant–butterfly samples revealed that A nthene usamba are δ 15 N enriched relative to the ants with which they associate. These data, based on the increase in δ 15 N through trophic levels, indicate that the caterpillars of these butterflies are aphytophagous and either exploit the ant brood of C . mimosae within the domatia, or are fed mouth to mouth by adult workers via trophallaxis. This is the first documented case of aphytophagy in A frican A nthene . Pupation occurs inside the domatium and the imago emerges and departs via the hole chewed by the larva. The adult females remain closely associated with their natal patch of trees, whereas males disperse more widely across the acacia savannah. Females prefer to oviposit on trees with the specific host ant, C . mimosae , an aggressive obligate mutualist, and avoid neighbouring trees with other ant species. Adult butterflies are active during most months of the year, and there are at least two to three generations each year. Observations made over a 5‐year period indicate that a number of different lycaenid species utilize ant‐acacias in E ast A frica, and these observations are summarized, together with comparisons from the literature. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society , 2013 , 109 , 302 – 312 .