Heathland is a thermophilous habitat that support one of the highest diversity of ants and myrmecophiles in temperate Europe. The ants in heathland build and occupy highly different nest structures: red wood ants construct large nests with a mound of organic thatch and with subterranean galleries in the sandy soil. These nests are typically formed around a wood stump.The facultative slave-raider Formica sanguinea can have different nest structures. They often build thatch mound nests, but these are typically smaller than red wood ant mounds and less structured. Formica sanguinea may also form simple ground nests inside the soil without organic mounds or the presence of wood. Lasius fuliginosus nests in trees in which they make larger carton constructions. Lasius brunneus is also a tree nesting (arboreal) ant, but does not form carton constructions. Different Myrmica and Lasius species and the ant Formica fusca have variable types of ground nests. On one hand, they inhabit subterranean soil nests, with galleries frequently around the roots of grasses within the sandy soil (ground sand nest) On the other hand, they live in and under dead wood (ground wood nest). Ground nesting Lasius and Myrmica species often display a clear habitat preference, favouring either ground wood or soil nests. For example, the ant L. platythorax and M. ruginodis prefer wood nest structures, whereas the congeneric L. niger and M. rugulosa are typically found in ground sand nests. Myrmecophiles and ant-associated aphids have different host ranges. Some species, such as Platyartrhus hoffmannseggii and Cyphoderus albinus can be found in association with all ant nests, other such as Amphotis marginata are restricted to one host species. Most generalist myrmecophiles can be found in red wood ant nest, but to find some very host specific species one needs to open nests of other species.
As taxonomically and funcionally diverse group of ants can be found in a very small area in heathland, these habitats are ideal to reconstruct interaction networks across ants and interacting partners. Currently we are exploring the dynamics of the ant-symbiont network in heathland. Below you find some interesting myrmecophiles I encountered:
Lomechusa emarginata with Formica fusca - Myrmica
Lomechusa emarginata is a fascinating rove beetle that alternates from host species during the year. They live as larvae in Formica fusca nests in summer and the adult beetles hibernate in Myrmica nests. Probably they are the most specialized myrmecophiles in temperate Europe. They are completely integrated into the host colony and are treated as true nest mates. Adults and larvae are transported in the nest, are fed and cleaned. They deceive their host ant with a battery of glandular secretions. They do not provoke aggression althrough they also consume the brood. In one nest I found more than 80 larvae and some adults as well. I collaborate with an ongoing project on the chemical ecology of this species with Luan Dias Lima and Ricardo Caliari Oliveira.
Amphotis marginata with Lasius fuliginosus
Amphotis marginata are flattened beetles that typically occur at the nest entrances and near the foraging trails of the ant Lasius fuliginosus, which builds arboreal carton nests. The beetle is notorious for its habit of pilfering food droplets, acquired through begging and tapping the mouthparts of ants.
Beetle larvae are more yellowish than ant larvae. They also have legs and often curl which make them very distinct
Lomechusa larvae rapidly rescued by their Formica fusca host
Lomechusa larvae and adult (middle photo) cared by the host ant
Haeterius ferrugineus with Formica fusca
Haeterius is a small histerid beetle typically associated with Formica nests. I mostly encountered the beetle in Formica fusca nests, but also once in a F. sanguinea mound. They often raise their body when an ant approaches. An overview of the records of this species in Belgium and Luxembourg can be found here: PDF
Dinarda dentata with Formica sanguinea
Dinarda dentata's preferred host is Formica sanguinea. This medium specialized beetle is able to steal food droplets from the host during trophallaxis. In the the nests of F. sanguinea I also regularly observed black Formica fusca workers, which are slaves raided by the F. sanguinea colony. Interestingly, I also find the congeneric Dinarda maerkelii in the same sites, but then with its preferred host Formica polyctena/rufa