American Hover Fly

Yesterday, an American Hover Fly (Metasyrphus americanus) came into our office at the Audubon Center at Francis Beidler Forest.


The American Hover Fly is a very good wasp mimic (note only one pair of wings versus a wasp's two pairs).  If you doubt this is true, watch the histrionics of anyone along the boardwalk or picnic area when one of these insects makes its noisy appearance.  It's only a fly, but you would have an impossible time convincing anyone of that fact.

You can learn more about hover flies (specifically, in Europe) here.  In the meantime, you need to worry about something other than these aphid-eaters.

Fauna Update

The salamander images from last week have arrived. The Slimy Salamander (Plethodon glutinosus) is shown on the notebook and the female Marbled Salamander (Ambystoma opacum) guarding her eggs.

Salamander images by Christina Bryant (slimy) and Michelle Baldwin (marbled)

Although not yet showing on their webpage, this month's edition of South Carolina Wildlife magazine contains an article by Steve Bennett describing the winter behavior of many of our state's amphibians. Most notably, heavy winter rains trigger explosive breeding episodes in some species. The cooler temperatures allow for more oxygen in the water, which is beneficial for adult and young amphibians alike.

The bot fly that we discovered earlier in our office has been tentatively identified as Cuterebra fontinella fontinella. Jeff Boettner, Plant, Soil and Insect Sciences, at University of Massachusetts-Amherst spotted our images on the web and noted that it was not the Squirrel Bot Fly (Cuterebra emasculator) that we later described on this blog. The previously-unidentified Cuterebra fontinella fontinella seeks Peromyscus (deer mice)as a host for its larvae. Apparently, there is also a bot fly that targets rabbits. Who knew? Well, somebody...but not us. You should be noticing that our insect species list continues to grow as we identify specimens. We welcome all those who are willing to study and/or identify our insects as they are a critical component of our old-growth ecosystem.

Bot fly images by Mark Musselman

Mystery Bot Fly

Several month ago, the fly shown in the images landed in the office at the Audubon Center at Francis Beidler Forest. Having never seen anything like it and being unable to identify it, we captured it in the name of science. We've narrowed the identification down to the genus Cuterebra, but we are not yet sure of the species. Based on the number of Gray Squirrels (Sciurus carolinensis) we have seen with warbels (the lumps [a.k.a.bots or wolves] that house the larvae as they feed on the host), we supect our specimen is Squirrel Bot Fly (Cuterebra emasculator).

Our specimen appears to be a female based on what looks like an ovipositor at the base of the abdomen. We're still trying to track down a resource on bot fly anatomy! The female does not deposit her eggs within or on the host. Instead she deposits her eggs in an area likely to be visited by the desired host. It isn't known how she determines this, but when a host brushes by, the egg is picked up. When a larva emerges from the egg, it will burrow into the host's skin forming the bot. It is unknown how great an infestation is required to cause health stress for the host or for young, if a nursing female host is involved. The larva remains hooked inside the host as it feeds until it emerges through its breathing hole and drops to the ground in which it will burrow and pupate.

Most bot flies have a specific wild animal host that they target, but humans and domestic animals can occasionally become hosts. In Central America, the bot fly, Dermatobia hominis, targets humans. If you don't like the sight of a palmetto bug, you would have a hard time dealing with Dermatobia hominis.

Although we're sure our specimen is not Dermatobia hominis, we would like to make a species-level identification. Please contact us if you can make such an identification.

Images by Mark Musselman