Apidae

The next specimen is a bumble bee, member of Apidae (Cuckoo, Carpenter, Bumble, and Honey Bees). Bumble bee species are differentiated by their yellow-black pattern. This specimen is a California Bumble Bee, based on its yellow thorax up to the wing joint and the single yellow band on the abdomen. When in the killing jar, this specimen extended all of its body parts, including its mouth parts and stinger. I generally avoid capturing bumble bees, as they are somewhat threatened, but I made an exception with this one. This bumble bee is very common on the west coast, hence the name.

Hymenoptera; Aculeata; Apoidea; Apidae; Apinae; Bombini; Bombus (Thoracobombus); Bombus californicus
Common Name: California Bumble Bee

Now to elaborate on Apinae and Bombus. Bumble bees can be orange, white, or yellow on black and most are over 20mm long. They are important pollinators of clover because they have such a long tongue. Most bumble bees nest in the ground, and only the fertilized queens overwinter. Some species of Bombus are actually parasites of other bumble bees and they are sometimes placed another genus, Psithyrus. The females of Psithyrus lay their eggs in other bumble bee nests for the larvae to be raised by that colony, often times by killing the host queen and releasing pheromones to "enslave" the previous queen's brood of workers.

Apidae

I went to Coyote Hills preserve with the family today, and caught a large bumble bee - however, since I already have a bumble bee specimen, and bumble bees are becoming threatened species, I decided to let him go. Before I released him, I took a few nice photographs and was able to identify him based on these photographs.

Hymenoptera; Aculeata; Apoidea; Apidae; Apinae; Bombini; Bombus vosnesenskii
Common Name: Yellow-faced Bumble Bee

This specimen is approximately 1.5 inches long, with two yellow stripes and a yellow face. Not much is known about bumble bees. They form colonies with usually 50 members, not as organized or specialized as honey bee or ant colonies. Because the founder female has to make or choose a burrow, it is not very large or she settles in a vacant burrow made by a ground animal. The area in which this specimen was caught was covered with ground squirrel burrows, so it is likely that one of those burrows contains the nest. In the first picture above, the bee is cleaning its face (cute, I think). Their populations are threatened by habitat destruction, diseases from commercially raised bumble bee populations, and invasive social insects such as the Pennsylvania Yellow Jacket, which is able to forage more nectar and compete for space.

I also snapped a photograph of this fly, which looks like a Tachinid fly, but could easily be a different family, as many similar looking flies are members of different families.