Lasius is a genus of formicine ants. The type species for this genus is the black garden ant, Lasius niger. Other major members, which live in drier heathland, are the cornfield ant, L. neoniger, and L. alienus. Other species include the temporary social parasites of the L. mixtus group and the hyper-social parasite Lasius fuliginosus. Lasius flavus is also a commonly seen species, building grassy hillocks in undisturbed pasture. In the Alps, these mounds – always aligned east to catch the first rays of the rising sun – have been traditionally used by goatherds as natural compasses.
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Insecta
- Order: Hymenoptera
- Suborder: Apocrita
- Superfamily: Vespoidea
- Family: Formicidae
- Subfamily: Formicinae
- Tribe: Lasiini
- Genus: Lasius
The general thing to see in Britain is that workers (non-fertile female) shades are black in color and are covered in small hair. The winged reproductive female (queen) is almost as big as a baron, because workers have a large pair of dark and clear wings in color, which flows after consent. Male has wings and is smaller than queens. Larvae is leagely grubes, and puppy white silk is protected inside Cocon.
Common brown to yellow ants with short and somewhat upwardly sloped dorsal propodeal surface in profile, and a notably longer posterior declivitous face; the flexor (ventral) surfaces of the middle and hind tibiae usually lack pilosity, but even when they have erect bristles, do not have the hairs arrayed in two parallel rows.
Although found in a wide range of habitats, this ant is perhaps most familiar as a garden species. It also occurs in scrubland and wet areas. It can only survive in grasslands providing that there are either stones or mounds of the yellow meadow ant (Lasius flavus) present.
Just mated L. (Cautolasius) queens have large fat stores, and can found colonies independently, after mating in the air, then sealing themselves in a small nest in soil or rotting wood. All or most of the species in other subgenera are parasitic during colony foundation, and must gain entry to a colony of a species of the subgenus Lasius (Lasius), or less often, on L. umbratus to rear their first brood. Nonetheless, it is remarkably difficult to find mixed-species incipient colonies, perhaps because the parasites preferentially invade or are most successful in invading very young host colonies, also difficult to find.
Many or all subterranean species have mutualistic relationships with root-feeding aphids, and all species in the genus are fond of honeydew. Epigeic species also gather extrafloral nectar. Aphids mutualists eat some of the young of their bugs, while non-mutualists commonly scavenge protein of dead insects and other carrion.