Species Bumblebee

Bumblebee

A bumblebee is any member of the bee genus Bombus, in the family Apidae. There are over 250 known species. They have been introduced to New Zealand and the Australian state of Tasmania. Bumblebees are social insects that are characterised by black and yellow body hairs, often in bands. However, some species have orange or red on their bodies, or may be entirely black

They are best distinguished from similarly large, fuzzy bees by the form of the female hind leg, which is modified to form a corbicula: a shiny concave surface that is bare, but surrounded by a fringe of hairs used to transport pollen (in similar bees, the hind leg is completely hairy, and pollen grains are wedged into the hairs for transport).

The blood or hemolymph, as in other arthropods, is carried in an open circulatory system. In fertilised queens the ovaries are activated when the queen lays her egg. It passes along the oviduct to the vagina. In the vagina there is a chamber called the spermatheca. This is where the queen stores sperm from her mating. The queen, depending on need, may allow her egg to be fertilised. Non-fertilised eggs become males, and only fertilised eggs grow into females and queens.

Like all bee tongues, the bumblebee tongue (the proboscis) is a long hairy structure that extends from a sheath-like modified maxilla. The primary action of the tongue is lapping, i.e. repeated dipping of the tongue into liquid. Bumblebees are typically found in higher latitudes and/or high altitudes, though exceptions exist (there are a few lowland tropical species).

Bumblebees form colonies, which are usually much less extensive than those of honey bees. This is due to a number of factors including the small physical size of the nest cavity, the responsibility of a single female for the initial construction and reproduction that happens within the nest, and the restriction of the colony to a single season (in most species). Often, mature bumblebee nests will hold fewer than 50 individuals. Bumblebee nests may be found within tunnels in the ground made by other animals, or in tussock grass as opposed to Carpenter Bees that burrow into wood. Bumblebees sometimes construct a wax canopy ("involucrum") over the top of their nest for protection and insulation. Bumblebees do not often preserve their nests through the winter, though some tropical species live in their nests for several years (and their colonies can grow quite large, depending on the size of the nest cavity). In temperate species, the last generation of summer includes a number of queens who overwinter separately in protected spots. The queens can live up to one year, possibly longer in tropical species.