Showing posts with label parasitic. Show all posts
Showing posts with label parasitic. Show all posts

Tuesday, July 10, 2007

Bee Fly




Bee Fly (Geron sp.)

Bee Flies in the genus Geron are among the smaller members of the Bee Fly family (Bombyliidae) found in the Ozarks region and look nothing like the Bumble Bee from which the family derives it's common name. They do have the hairy bodies and long, slender proboscis that are found in many family members, however. This particular Bee Fly was nectaring on an oxeye daisy during early June. While adults feed on nectar, their larvae are parasitoids or predators on bee larvae, particularly those solitary bees that lay their eggs in burrows excavated in the soil.

Some Internet sources say that when the female solitary bee goes in search of more leaves or pollen, the Bombylius female hovers at the opening of the burrow. While still hovering, she ejects an egg inside the tunnel with a flick of her abdomen. Maybe ... but I'll believe it when I see it. Another source notes that a female Bee Fly can sometimes be seen sitting in very loose soil, vibrating her butt like mad, so that the dirt is actually thrown outwards. I have seen something like this behavior, but am not willing to accept that she is gathering sand to coat her eggs so that they don't dry out, presumably so that she can chunk them down a solitary bee tunnel without harm. Instead, I accept that the female Bombylius is dipping her abdomen to oviposit, laying her eggs in the soil near a host species. When they hatch the larvae will feed on immature stages of beetles, bees, wasps, butterflies/moths, or on eggs of grasshoppers.
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Friday, July 06, 2007

Weevil Wasp




Weevil Wasp (Cerceris sp.)


This is another of the many small, parasitic wasps that are very difficult to identify down to the species level using only a photograph. Most Cerceris prey on weevils, although a few prey on solitary wasps and bees. They belong to a larger family (Philanthinae) called Digger Wasps because the females excavates a hole in the soil where she lays her eggs after provisioning the nest with her prey of choice.
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