Bombus terricola

Bombus terricola
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Apidae
Genus:	Bombus
Species:	B. terricola
Binomial name
Bombus terricola Kirby 1837

Bombus terricola, the yellow-banded bumblebee, is a species of bee in the genus Bombus. It is native to southern Canada and the east and midwest of the United States. It was at one time a common species but has declined in numbers since the late 1990s. It is a good pollinator of wild flowers and crops such as alfalfa, potatoes, raspberries and cranberries.^[1]

Description

The yellow-banded bumblebee is black and yellowish-tan, and has a characteristic fringe of short yellowish-brown hairs on its fifth abdominal segment.^[1] The queen is about 18 mm (0.7 in) long. The front half of the thorax is yellowish-brown, as are segments 2, 3 and 4 and the sides of segment 6 of the abdomen. The other parts of the thorax and abdomen are black. The worker is similar in appearance to the queen but smaller at a length of 9 to 14 mm (0.35 to 0.55 in). The male is intermediate in size, being 13 to 17 mm (0.5 to 0.7 in) long. In the male, abdominal segments 2, 3, and 7 are yellowish-brown as usually are the sides of abdominal segment 6.^[2]

Conservation status

Like several other North American species in its subgenus Bombus, the yellow-banded bumblebee has suffered sharp declines in numbers since the mid-1990s. The suspected culprit is either Nosema bombi, a unicellular parasite, or another imported protozoan parasite Crithidia bombi. The yellow-banded bumblebee has disappeared over large parts of its range, but is still present in Vermont, New Hampshire and Maine where the population appears to be stabilizing and in the Great Smoky Mountains where the population seems to be expanding. It is not clear whether this is because it has developed some resistance to the parasite or whether the parasite has not yet spread into these parts. The rusty-patched bumblebee (Bombus affinis) has suffered an even more steep decline. It will become clearer over time whether populations of these bees will remain viable or whether the species will become extinct.^[3]

References