I believe this is one of the Tachinid Flies, family Tachinidae. The second largest fly family, there are 1,350 species in North America. Here is a link to the pdf checklist of North America. Local list in progress. Eastern list is now here. Creating the key is a daunting task so far. Four subfamilies are listed: Dexiinae, Exoristinae, Phasiinae and Tachininae. Most of these guys are restricted to particular hosts. Many attack caterpillars of the butterfly and sawfly species but some attack beetle larvae.  Eggs are laid directly on the host or on plants that are inhabited by the host. The tachinid larvae feed internally. The hosts almost invariably die. I have found the adults on flowers before and I have seen a long-legged darker species similar to this one. This guy (or gal) flew into my car and landed on my net handle. Insects seem highly attracted to my net handle. Hard to say. Perhaps my aroma?

In fall this yellow-rumped species which is likely in the genus Belvosia (in the Exoristinae) shows itself and frisks the flowers.

This is another Belvosia or the same species in early summer from Indian creek area. This is a big bulky fly. Hulking you might say. Loud buzz.

The, well, shining, spiny ass end of the same fly. Yikes.

One of the Tachinids with a comb on the hindleg (comb-footed flies). Very nice animals. Appears these are in the genus Trichopoda and there may only be about six species in the genus. There is a similar black species that flies in the fall. Elusive so far.

Visible combs here as well with slightly different red distribution. One needs a book on the Tachinids alone. This comb looks heavier than the above.

Very large Trichopoda from some fall flowers. Over an inch across the spread wings though very similar in appearance to the smaller comb foot several shots up.

Appeared to have the Syrphid cross vein but alas I was misinformed by my eye. A fly man beyond my capabilities believes this is a Tachinid in the Phasiinae subfamily. Very dark species and very striking for a fly don't you think? And though it appears to have two extra wings, I believe that is due to fly sex. The underlying partner is mostly obscured.

Another comb foot which looks very close to Bob's paired species above. This one was frisking flowers in fall over near Toadsuck beach. Amazing variety or just my confusion at this big group for now.

No combs on the leg visible. Sort of looks like a cross between the above two flies. Same facial structure. Really nice flies though. I could believe this was the female to the fly two shots up.

No fly has impressed me more than this one recently. A breath-stopping Tachinid fly which is likely in the genus Cylindromyia. It is a genus of about 20 or less in the US. They are in the Phasiinae. I think most are narrow-waisted. They are parasitoids as are all of the Tachinids.

Even the same tilted pose in this fly from Choctaw NWR. Also in Cylindromyia. Less wing marking and lacking the purplish prunescence of the above. Collected, so I will sort this out soon.

Also seems to be close enough to the narrow-waisted Tachinid above to be in the genus Cylindromyia.  Eric Eaton thinks this may be Cordyligaster, which is another narrow-waisted Tach with only one species in the east. Dark and shaded woodland is where I found this one and it was very wary up on its leaftops like a robber.

This must be the same species. And I am now working on the species in this group with a classic paper donated by Judy Semroc. Taken in Choctaw NWR in SE AR. Specimen collected so I will sort out whether this is in a different genus soon.

A big Tachinid. Had its little area on the path and kept going there. Much larger than the fly just below though they were on the same trail on the same day. I am in the process of obtaining the US Tachinid catalog. We will see.

Smaller and purpler version. This one was a dervish on the leaf top. Spinning and running to the edges. Ruby red eyes.

Must be a relation of the above. These Tachinids seem to guard their leafy perches closely, I assume on the lookout for rivals and mates.

Very common in the horsetail area of Toadsuck.  Buzzing in several areas and landing up on leaf tops. Wide eyed and wary. Seems to be a common late summer fly in several areas. May be a relation or member of the genus Archytas. We have about eight or so expected species in that genus locally.

Impressive pair of flies. On this May day in Point Remove this was the commonest fly around down in the low vegetation. It is almost certainly an Archytas species. A genus known for the kidney-bean shaped last antennal segment. I think I have taken three in the genus and they may all be this species. There are about 13 species in the east. That moist looking structure was attracting three and four flies at a time, all of this species. It may have been fungal.

Very unusual fly. So unusual I doubted it was a Tachinid. But I was wrong. Apparently it is in the genus Zelia. Of which there are about 15 in the US by Nearctica but only 7 or 8 in the east. I have no info on habits. But these were buzzing around a pine trunk making loops over each other (there were two). Always perched head down. Seemed very close to another pair I had seen near this same area in the summer. Those two 15mm flies fell from the trees onto the ground in a tussle. I was amazed by them. But they took off before I could shoot them.

Small pair of Tachs up on the vegetation. Cuddling, I guess. I did not take them, so they remain unknown for now.

More Tach images