large, mating bugs – Georgia
Location: Atlanta, Georgia
October 8, 2011 9:11 am
We saw these 2 insects (appear to be mating) on a sunny, warm day in early October 2011 in Atlanta, GA. They are quite large – perhaps wingspans of 6 inches and leg spans of 12 inches with almost iridescent wings. We’ve lived here almost 10 years and had never seen these, although we may be seeing more next year if mating was successful. Anyone know what they are? Thanks!
Signature: Dan and Ade

Giant Crane Flies Mating

Dear Dan and Ade,
Most people who encounter Crane Flies mistake them for very large mosquitoes, but unlike Mosquitoes, Crane Flies do not feed on blood.  A common name we have encountered for Crane Flies is Mosquito Hawks, however, Crane Flies do not prey on Mosquitoes.  It is generally believed that adult Crane Flies do not feed, or that they subsist on a liquid diet.  Your individuals are Giant Crane Flies, Tipula abdominalis, and according to BugGuide:  “large size coupled with black velvety patches on thorax is diagnostic feature.”  The God of Insects website has a nice synopsis of the life cycle of the Giant Crane Fly that is copyright 2003 by Barbara Strnadova that states:  “This striking crane fly is found wherever there are freshwater streams in central and eastern North America. The large, plump larvae, often called “leather jackets”, are aquatic. They can be found under rocks, in debris and in mud along the bottoms of streams in many different habitats. The larvae are detritivores and are abundant wherever there is sufficient rotten leaf litter. Two generations of adults emerge each year; one May-July and another beginning in August or September. While Tipula abdominalis is one of the largest crane flies, many crane flies in the genus Tipula are also quite big. These large flies are often mistaken for giant mosquitoes, while in some parts of their range these giant flies are called “Mosquito Hawks”, a name that really refers to the famous Green Darner Dragonfly. Crane flies are called “Mosquito Hawks” or “Mosquito Eaters” under the mistaken assumption that they are some kind of predatory fly. The reality of the situation is quite different, for they take sustenance only from flower nectar – if they eat at all. They cannot bite so although they are huge, you have no need to fear them. Tipula abdominalis is often attracted to lights at night.”  Since the larvae are aquatic, you would need a freshwater stream nearby for this mating to result in procreation, however, since Crane Flies are feeble fliers, we can presume that there is a nearby stream.  Here is a photo of an aquatic larva of the Giant Crane Fly from BugGuide.