February 28, 2018

Exelis pyrolaria and Exelis ophiurus in Texas

It is a fact that Exelis pyrolaria and Exelis ophiurus are difficult to separate based on general appearance. I really didn't think they were, based on the few pics at MPG and on moths I've seen and identified (or thought I did) in the past. But the more I looked into the identification of the Texas SWGs (slender-wing geometrids), the more I realized that these two Exelis species often cannot be separated with certainty on the basis of general appearance. I went to BOLD public data pages where there are 5 E. ophiurus and 7 E. pyrolaria on the public records data pages. As is unfortunately the case on BOLD, the genetics may say one thing, but most of the specimens are scaleless, patternless, and completely uninformative.

There are 25 pyrolaria specimens on the BOLD taxonomy page, but BOLD identifies them as 7 pyrolaria (same as on the public data page), 1 Exelis dicolus, and 17 unidentified. I cannot figure out how to look at the locality data for any of these specimens except the 7 on the public data page for the species. Of those seven, four 4 from Bartlesville OK (the NE corner of that state) two are from KY and one from GA. At the BOLD taxonomy page, the distribution of E. pyrolaria is described as east of the Mississippi River and south of southern Illinois. The map shows a dot east of the Mississippi River and one in OK.

There are 9 E. ophiurus specimens at the BOLD taxonomy pages. Visually they are not particularly useful. BOLD identified these as 5 E. ophiurus and 4 unidentified. Again, I cannot figure out how to see the locality data for those four specimens. Of the five identified, one is from Florida, and while BOLD does identify it as ophiurus, it places it in a separate bin with some Atlantic seaboard Tornos scolopacinaria. Of the remaining four identified specimens, one is from OK about 100 miles north of Dallas, and the other three are from Texas, (Irving, Pedernales Falls, and Sanderson.)

I cannot explain the three locality dots on the MPG in the Edwards County area for E. pyrolaria. I think there is a good chance that those are based on visual identifications, but it’s possible one of the dots is a specimen that Ann H sent to BOLD.

The original literature, (Rindge 1952) did provide some useful information. In this paper, Rindge (1952) describes dicolus and ophiurus as new species. Rindge saw only pinned specimens. Early in the paper he recommends that genitalia be the basis for identifying the species. Rindge looked at 90 specimens of Exelis (3 holotypes and 87 others). He looked at 37 ophiurus specimens, 6 dicolus, and (I assume) 47 pyrolaria.

Rindge described pyrolaria (Guenee, 1857) as a dark moth species--dark gray or dark grey-brown. Of all the Exelis, Rindge states that pyrolaria can be “recognized by the dark gray color of the wings, although in old or worn specimens this fades to a grayish brown.” I mention that the gray live specimen of pyrolaria in the image by Mark Dreiling and pictured on the MPG page for pyrolaria is one that is barcoded and identified as pyrolaria at BOLD.

Rindge described ophiurus (this is the original description) as more pale (than pyrolaria) and ochreaous in color (reddish-brown). Neither of these characters may apply to the live specimens we deal with. I haven't seen a live specimen I'd identify as "ochreaous" in color. However, of the 7 pinned specimens at BOLD, considering the scaleless condition of several, all are dark specimens. One of the 5 ophiurus BOLD specimens (a beat-up old crappy TX specimen from Irving) could be considered dark.

The type locality for ophiurus is Texas: Burnet County: Burnet. Rindge states in the description of ophiurus that is it paler than pyrolaria, and the lines on the wings are much more distinct--however, the discal spot that both typically have is "weaker" in ophiurus than in pyrolaria.

Perhaps most helpful. Rindge found pyrolaria only east of the Mississippi River. This statement is repeated by BOLD, although their records include the four from northeast OK. All of Rindge’s specimens of ophiurus were from Texas and there are paratypes from Bexar, Val Verde, Edwards, McKinney, and Terrell counties. All six dicolus seen by Rindge were from Arkansas.

So basically, in the absence of dissection of the genitalia or barcode to indicate otherwise, I consider it most likely that the Exelis found SW Hill Country/ Edwards Plateau/Trans-Pecos are Exelis ophiurus. I see no evidence that pyrolaria ranges anywhere near that far into Texas. I'm not aware of definitive evidence to indicate that pyrolaria is in Texas even to Austin.

Posted on February 28, 2018 19:20 by ptexis ptexis | 3 comments | Leave a comment

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