Friday, July 31, 2009

Giant Resin Bee (Megachile sculpturalis)




The term GIANT resin bee is a little misleading. M. sculpturalis is a giant among resin bees which tend to be small. It is about the same size as a bumble been but more cylindrical and not as heavily built. The females tend to be larger than the males. The head and abdomen of the giant resin bee are black. Dense yellowish-brown hairs cover its thorax. Their wings are dark, but still transparent.

Giant resin bees are native to Asia. They were introduced into the United States in North Carolina in 1994. The exact means of introduction is not known, but via ship is suspected. They have since spread throughout the southern U. S. In the short run, there are no known harmful effects resulting from Asian Resin Bees, at least as far as humans are concerned. They are not aggressive and will seldom sting unless trapped. In the long run, it is not yet know what effects M. sculpturalis may have on native pollinators. Their size could give them a competitive advantage. On the down side, Giant Resin Bees are also known to be excellent pollinators of kudzu -- as if it needed any help in thriving.


According to North Carolina State University, Giant Resin Bees have large jaws, which the females use for carrying nest material. People usually encounter giant resin bees around buildings and wooden decks, because they commonly nest in vacant carpenter bee tunnels. These bees will also nest in small spaces between the boards of a building and in dry rotten logs with tunnels bored by other insects.


The female bee nests alone and begins by preparing a cell in an existing tube or narrow cavity, using resin and sap collected from trees. Other materials such as bits of rotten wood and mud are also used in nest construction. Next she collects pollen and carries it to the nest on the underside of her hairy abdomen.


After completing several pollen collecting trips, she lays an egg on the pollen ball in the cell. Then she seals it, and prepares another cell. Continuing in this fashion, one female can complete about 10 cells. If the entrance of the nesting tube is directly exposed to the outside, the tube may be noticeably sealed with a resin, wood and sometimes mud cap. After the eggs hatch, the larvae feed on the pollen and spend the winter within their cells. The larvae pupate in late spring and the adult bees emerge that summer.

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5 comments:

Lisa at Greenbow said...

What a fantastic photo of this bee. I can actually see the eyes. Interesting information on this handsome bug. I can't believe it likes kudzu. Too bad about that.

birdy said...

A very detailed capture of the resin bee probably on some sort of thistle flower. Thanks for sharing the image and information.

SAPhotographs (Joan) said...

Beautiful Marvin. One does tend to wonder what the situation will be like with these "invaders" in 20 years time. Great information.

Have a wonderful week Marvin.

Kelly said...

...beautiful photo of such a little fellow! Thanks for the info as well!

Pat - Arkansas said...

Fantastic photo, Marvin, and very interesting information, as always.