Fiery-tailed Bumble Bee

Bombus ignitus is a large bee characterized by a medium length tongue. Females have black bristles that cover the back of the thorax and the mid-legs. The abdomen is separated into five tergum. Starting from the thorax, the first three terga are black in color, whereas the fourth and fifth terga are orange-red in color. Males are characterized by golden yellow bristles that form two bands on the anterior and posterior thorax. Like the female, the male has an abdomen separated into five tergum. Starting from the thorax, the first two terga are golden yellow in color, differentiating males from females. The third tergum is black in color. The fourth and fifth terga, like the female, is orange-red in color. Compared to the female, the male compound eye is small. The antenna of males are shorter than the antenna of females, reaching only to the base of the wings. Compared to the males of other bumblebee species, the males of B. ignitus have greatly broadened penis valves that flare outwards to form a funnel shape. The queen has a body length of 19 mm (0.75 in). Workers have a body length of 15–17 mm (0.59–0.67 in). Males have a body length of 17 mm (0.67 in).

Bombus ignitus is found in the Palearctic realm, primarily in East Asia. This includes the more humid and temperate areas China, Japan, and Korea. Populations of B. ignitus can be found at a mean altitude of 1425 m at the western, southern, and eastern foothills of the Sichuan Basin. Though uncommon, populations have been found at lower altitudes.

Bombus ignitus is monandrous; the queen mates with only a single drone to form a colony. All workers and new queens, as a result, are descendants of the queen and a single drone. This monandrous behavior decreases the amount of genetic variation present in a single colony relative to that of a polygynous or polyandrous species.

The protein BiVSPI, Found in the venom of B. ignitus, has been identified as a serine protease inhibitor. BiVSPI exhibits antimicrobial functions, and has been found to inhibit the growth of Gram-positive bacteria and fungi. The cDNA of four antibacterial peptide genes - apidaecin, hymenoptaecin, abaecin, and defensin - were isolated and cloned from B. ignitus. Synthesized abaecin has been shown to inhibit the growth of Gram- negative bacteria, but had little inhibitory effect towards the growth of Gram-positive bacteria.

== References ==

Bombus ignitus is currently used for agricultural pollination in China and Japan. The species has been chosen as a reliable species for commercial mass-production in Korea, though issues of diapause management must still be addressed. B. ignitus was chosen over the already established bumblebee, Bombus terrestris, for fear of competition or genetic contamination by mating with native bumblebee species.