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I photographed this teneral female clubtail on the US side of the Rio Grande at Santa Ana NWR, Hidalgo County, TX, 25 May 2002. It was very weak, (caught by hand) and most likely emerged right there at the river. Unfortunately, I did not have a collecting permit. Length was estimated as 50-55 mm. Sid Dunkle suggested that it was a new species for the US. Dennis Paulson and Nick Donnelly identified it as Phyllocycla breviphylla or elongata, with the nearest known occurrences being in San Luis Potosi and southern Coahuila, MX, some 200-300 miles to the south. Whether there is a viable population in the Rio Grande is unknown. A specimen, of course, would be highly desirable.
2004 Update: In May Omar Bocanegra collected two female Phyllocycla breviphylla on the Rio Grande in Cameron County, downstream fron Santa Ana. In August Martin Reid photographed what is believed to be a male Phyllocycla in Hidalgo County, upstream from Santa Ana. See Martin's photos here.
Thanks to Nancy Adams and Oliver Flint I was able to look at specimens in the U.S.N.M., Washington DC. The collection has two females of Phyllocycla elongata, taken in 1937 and 1966. Belle (1975,1976) described a new species, P. breviphylla, and gave distinctions from P. elongata. Based on those papers, I believe that the two U.S.N.M specimens may be closer to breviphylla. Donnelly however, believes that the distinctions between these two forms are very slight, and that they are best thought of as one species. (Personal communication.) Dennis Paulson furnished photos of male elongata, and male and female breviphylla specimens. Comparisons of these specimens and photos with the TX photos are given below:
Head comparisons San Luis Potosi spec. Shows 3 cells in HW subtriangle Veracruz spec. ~60 mm San Luis Potosi spec. ~52 mm Comparison with Paulson specimens
Discussion of specimens: Belle (1975, 1976) and Forster (2001) give two features to separate females of elongata and breviphylla. In elongata the first pale antehumeral stripe is as wide as or narrower than the second. In breviphylla it is for the greater part distinctly wider than the second. In elongata the green of the metepimeron reaches the rear border of the segment. In breviphylla the metepimeron has a green band on the middle part of the segment. Based on these features, I believe that the Veracruz and San Luis Potosi females shown above are breviphylla. (The San Luis Potosi female is with a male caught in tandem, which also appears to be breviphylla.)
The two female specimens are close in most respects to the TX photos. One is 52 mm long which fits with my estimate of 50-55 mm. The pattern of pale markings on the face, and the first and second antehumeral stripes match closely. The abdominal markings and shape of the appendages are very similar. The mesepimeral and metepisternal thoracic stripes differ slightly. The mesepimeral is broken on the TX individual. The metepimeral stripe is narrow on the specimens, not extending to the rear margin. In the TX photos, I think I can see that rear edge of that segment is beginning to darken, so that it may match breviphylla, but that is a guess. I thought that the TX female was less than a day out of the water, so it could be expected to darken some more.
Comparing the Texas photos with Paulson's specimen photos, the pale thoracic stripes of the Texas female appear intermediate in width between those of the male elongata and the female breviphylla, perhaps closer to the latter. The metepimeral pale stripe on the Texas female is relatively broad, closer in width to that of the elongata male than to the breviphylla male and female. Again, it could be expected to darken with maturity.
The key in Needham, Westfall, and May states that Phyllogomphoides has two or more cells in the hindwing subtriangle, while Phyllocycla generally has one. The TX female seems to have 3 cells in the hindwing subtriangle, but the female from San Luis Potosi also has 3 (see photo above.)
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I would like to thank Sid Dunkle, Dennis Paulson, Nick Donnelly, Jerry Daigle, Rosser Garrison, and Enrique Gonzalez for commenting on the photos.
Please send comments to Dave Czaplak, dma3@aol.com