Halictus malachurus

Taxonomy
Halictus malachurus is a small British subsocial bee belonging to the order Hymenoptera family Andrenidae. Early taxonomists mistakenly assigned the sterile worker females of Halictus malachurus to a different species named Halictus longulus, although they are in fact different forms of the same species (see section entitiled Life Cycle). Halictus malachurus are an interesting species as they exhibit some of the characteristics associated with their eusocial relatives (e.g. the Western honey bee Apis mellifera) whilst retaining some characteristics associated with the more solitary bees (e.g. Halictus quadricinctus).

Habit & Habitat
Halictus malachurus tend to aggregate in pseudo-colonies in favourable locations, where bees individually excavate separate nesting burrows close together in hard soil. These clusters, sometimes containing hundreds of burrows, are not true colonies, as each nest burrow is distinct from another. Halictus malachurus feeds on pollen and nectar, mainly collected from the flowers of willows and dandelions when they are in flower in the Spring.

Life History
The females of Halictus malachurus, following fertilistation the previous Autumn, begin to appear in the Spring, when plenty of food sources are available to sustain them after the long over-wintering period. Although several females usually see out winter in the same burrow with little conflict, they now act aggressively until a single female is left in possession of the burrow, leaving the evicted females to obtain or excavate burrows of their own.

Each female in possession of a nest tunnel then begins to build brood cells in short side passages which she excavates to the side of the main passage. Immediately following construction each brood cell is mass-provisioned with a mixture of pollen and nectar in the form of a dry, doughy pellet. An egg is laid on each pellet and the individual cell sealed by the female. The resident female then goes on to construct more, similar cells containing eggs and pollen nectar-pellets.

By the end of May larvae from the earliest eggs are full grown and start pupation, emerging from their cells as perfect insect by mid-June. These adults are all non-reproductive females, somewhat smaller than their mother and with different markings on their cuticle.

The original maternal female bee remains within the nest and guards the entrance to the burrow, whilst her non-reproductive daughters go out foraging for food, and help in the construction of new brood cells, which the original maternal female lays eggs in.

By the beginning of August reproductive females, the same morphology as their mother, as some males appear from the eggs laid by the original maternal female. During sunny weather, the males mate with the new reproductive females from both their own and separate nests, although they do not attempt mating with the non-reproductive females. Impregnated females continue to live in their mothers nest, although it is thought that they only forage for their own food and do not contribute to the rest of the nest.

With the arrival of the colder Autumn weather the males and non-reproductive females die off, and the impregnated reproductive females go on to form new nests and repeat the life-cycle.