Ophiogomphus adult specimen from sw Georgia, now confirmed to be O. australis, new state record
On 6 Apr 2005 this male Ophiogomphus was found in a Nature Conservancy Preserve in Early County, GA. This county is in southwestern Georgia, right on the Alabama border, and one county north of Florida. This location is in the Coastal Plain about 85 miles south of the fall line. Approx lat/long is 31 12N and 085 05W.
click on either thumbnail to see a full size version
It was found along this power line cut, on a dead tree limb in the grass, about 1/2 mile from a small stream.
Some shots of the first order stream, steady flow, and fine gravel bars. In Feb 2006 Steve Krotzer and I found many larvae of three age classes here and in a nearby stream that eventually combines with this one.
By the time we checked out the stream it was cloudy and we saw no adults at the stream.
The specimen was 45 mm long in life, and now measures 44 mm. The abdomen is 30 mm and the hindwing is 24 mm if I'm measuring from the right spots. These measurements are close to O.i. incurvatus (40-43, 29-32, 24-27) but too small for O.i. alleghaniensis (47-49, 34-36, 27-30) as printed in Needham, Westfall and May (2000). O. australis is listed as 44-46, 32-35, and 24-28 for reference.
Here are shots of the appendages.
Shot on left from 2005, secondary genitalia oriented the same as Fig 236 in N,W+M. Most closely resembles O. i. incurvatus but might be due to the angle I took this shot. Now, from 2006, shots of RM1 and 2 (Reared male 1 and 2) at middle and right. These look much more like O.i. alleghaniensis.
Shot on left from 2005, side view of cerci and epiproct. Looks to me closer to O.i. alleghaniensis based on cerci shape, with spine on epiproct taller and more sharply pointed than O.i. incurvatus and too far from the tip of the cerci. On right, shot of RM1, with shorter spine, about halfway between typical O.i. alleghaniensis and O.i. incurvatus.
dorsal view of tip of abdomen, with epiprocts in focus.
dorsal view of tip of abdomen, with cerci in focus. Also looks closer to O.i.
(or O. australis) in shape.
ventral view of tip of abdomen.
So far, after examining three of the 2006 males dorsally, the cerci and epiprocts look very similar to the 2005 specimen.
Comments: O. incurvatus is not known from south of the fall line except for some larvae collected by Ken Tennessen and Steve Krotzer in south Alabama near Monroeville. They successfully reared some adults but have not found any adults in the field. The taxonomy of those specimens is unclear so far. This location is about the same latitude as the location for the ones on this page. Of the two described subspecies, O.i. incurvatus is thought to occur on the east side of the Appalachians down into the GA Piedmont and to the fall line. O.i. alleghaniensis is thought to occur on the west side of the Appalachians into north AL. There are also specimens of another Ophiogomphus species from the Eglin AFB FL area.
This specimen appears to me to have a mix of characters of both known subspecies of O. incurvatus as well as some features similar to the other known very southern snaketail, O. australis. J Daigle states:
I can only find a very few photos of O. incurvatus online or published, but the lateral thoracic stripes on the GA Ophio do not appear to match the O. incurvatus pattern as Jerrell states above. Steve Krotzer notes that the caudal appendages also resemble O. australis and wonders:
"if it's not clinal variation causing a lot of the differences in thoracic pattern coloration, with perhaps isolation leading to speciation occurring now and manifesting itself in slight differences in hamules/caudal appendages."
and notes the need for more examples of all of these individuals from different locations, including a series of males, females, and larvae. He also notes that this is easier said than done!
I was able to go back on 8 Apr and 24 Apr but found nothing.
On 11 Feb 2006, Steve Krotzer and I made a larval sampling of both this stream and another smaller one in the same small drainage. We found very healthy populations of Ophiogomphus in both streams, with almost 20 final instars found. Here is a photo of one of them:
We will continue to search for adults down here, but the taxonomy may be unresolved for some time...
On 27 Feb 2006 I went back and captured 10 final instars, which I brought home and put in a tank hoping to rear them to adulthood. Here is one of the larvae.
Update 14 Mar 2006. Except for one larva which died soon after going in the tank, there has been little activity since. However, today two males emerged starting around 0900. One did not like the rock he came out on, which was clear of the water but wet, and went back in the water. I added a dry rock to a different small tank and put him on it, under water, and he came right out and immediately emerged. I won't have full adult photos for a few days, but for now here are a few shots of the emergence sequence today. Both males appear to be in good condition, although the first one's wings do not appear to be properly or fully formed. The lateral thoracic pattern on both males appears to be identical to the one from 2005, with a full dark posterior stripe but a thinner incomplete anterior one.
Second one face to face with first one, almost completely transformed.
All the second one, on the dry rock
Update 18 Mar 2006. A total of 7 Ophios have now emerged, 6 males and 1 female. With the exception of 1 male who did not emerge properly, had pretty mangled wings, and died within a day, all are still alive. I just gave them some water this evening, and maybe that will help them survive a bit longer. Here is the emergence tally so far:
3/14: 2 males
3/15: 1 female
3/17: 3 males, including the one which died very quickly
3/18: 1 male, with another larva sitting on one of the rocks half in and half out of the water, don't know what will happen there.
3/19: the one half in and and half out emerged today, a male, and just after that another one emerged, a female.
Update 19 Mar 2006. With the male and female that emerged today, all 9 that survived the initial trip from the stream to the tank emerged!!
Here are a few photos of the first female that came out on 3/15.
Update 20 Mar 2006. Several of the tenerals have now died and become specimens. Here are a few shots of the first female:
Shots on left show lack of occipital and post-occipital horns, although it does have very small bumps where the occipital horns would be (best seen in second image, looking toward the front of the head). The last image on the line, on the right hand end, is the same angle on the head of the second reared female. Note that this one looks identical to the first one.
Update 26 Mar 2006. I spent a few hours searching the surrounding area yesterday (3/25) , including adjacent counties (counties are very small in Georgia), and could not find any similar habitat that I could get access to. Much of the promising topography was behind closed gates and fences. I then went back down to the site to check for exuviae, final instar larvae, and adults. I did not find any final instar larvae or exuviae, but I did capture an adult female (from the same stream as the reared ones and the male from 2005 but about 1-200 meters upstream). Here are some shots of the female:
Now, this is where it gets interesting. This female has one occipital horn! The other side is either broken off or didn't develop.
Note the obvious horn on the right, which is unlike the previous (reared) females. This individual does not have post-occipital horns, and neither do the two reared ones. I don't know why it has a horn on one side and only a knob like the reared ones on the other side. Again, these three females are all from the same small stream.
Update 1 Apr 2006. Jerrell Daigle, Marion Dobbs and I spent about 5 hours here yesterday looking for adults, and Jerrell found four of them on one small section of the same stream the others have come from, in the only section out in the open where it goes through a power line cut. Three males and one female, and the female has occipital horns (two!) similar to the one on the other adult female I caught 3/26. She did not appear to have any post-occipital horns. Here are some comments from Jerrell, with notes on the four he collected (note he is talking about two channels of the same stream here):
Pasted below are some shots of geographically close Ophiogomphus:
(c) Theresa Thom. Note these images are very large!
This female is one of the "FL" ones from Eglin AFB near Niceville FL. Note lateral thoracic pattern.
(c) Steve Krotzer
This female is O. i. alleghaniensis, from Tuscaloosa AL in 2005. Note really obvious occipital horns, set very close together.
(c) Henning von Schmeling
This female is probably O.i.incurvatus from north GA in 2005. You can see separated occipital horns in the large res original.
Summary of female southern Ophiogomphus epicranial characters courtesy of Jerrell Daigle:
|O.i.incurvatus||O.australis||FL sp.||AL sp.||GA sp.|
|Occipital horns||yes||no||no||yes||no/yes... not clear|
This map shows the region in detail. The solid green range is the approximate known range of Ophiogomphus incurvatus. The subspecies O.i.incurvatus is thought to occur on the eastern side of the Appalachians into GA, and O.i.alleghaneinsis is thought to occur on the western side into AL. The affinity of the three southern types is as yet unknown. The taxonomy and affinity of all these species is virtually unknown at this point! About the only thing for sure is that we need larger series of all these insects, except possibly O australis which is pretty well known.
Jerrell Daigle, Marion Dobbs, Steve Krotzer, Ed Lam and I spent all of 3/30/2007 at this preserve, and collected 3 male and 5 female specimens. We saw several others as well. We did not find any exuviae or final instar larvae. Here are photos of a couple of the females:
We probably have a decent series of this population now, and so the next things to try are to obtain more specimens of the south AL individuals or the FL individuals... but that will not be easy. Additionally, Steve Valley is scanning males from each of these populations so we can try to compare appendages.
Further comments welcome!! Updated 29 Oct 2014, with confirmation that this is australis..
Please send any comments to me at firstname.lastname@example.org
All photos (c) Giff Beaton 2007 except as noted.