PROC. ENTOMOL. SOC. WASH. 85(3), 1983, pp. 552-556 A NEW GENUS AND SPECIES OF GEOMETRIDAE (LEPIDOPTERA) FROM BIG BEND NATIONAL PARK, TEXAS Douglas C. Ferguson, Andre Blanchard, and Edward C. Knudson (DCF) Systematic Entomology Laboratory, IIBIH, Agricultural Research Ser-vice, USDA, % National Museum of Natural History, Washington, D.C. 20560; (AB) 3023 Underwood, Houston, Texas 77025; (ECK) 804 Woodstock, Bellaire, Texas 77401. Abstract.— K new genus, Astalotesia, is described by D. C. Ferguson, and a new species, A. bucurvata, is described by A. Blanchard and E. Knudson. It belongs in the tribe Melanolophiini Forbes. The male and female imagines, genitalia, and male wing venation are figured. While collecting with UV light trap at Big Bend National Park, Texas, in March 1982, E. C. Knudson took a small series of an unfamiliar geometrid, which was later matched to a single specimen in A. Blanchard's collection, taken 1 1 years previously at the same locality. Upon dissection, the moth proved to belong to the tribe Melanolophiini Forbes. However, it possessed an unusual combination of characters that did not allow placement in any existing genus. Assignment of the new genus to the Melanolophiini was based on a comprehensive assessment of adult characters. The paired, comblike structure on the anterior margin of the eighth sternite of the male and the wide, flat, modified scales associated with it (but arising from the posterior margin of the seventh sternite) (Fig. 5), together with the unsealed branches of the bipectinate male antenna, almost always serve to distinguish moths of this tribe. Of nine genera examined, the posterior abdominal comb is lacking only in Vinemina McDunnough, and is vestigial in Carphoides McDunnough. These two genera have also lost the modified scales, of which usually two to four pairs are present in other genera. Most melanolophiine genera also have two other sec-ondary sexual characters on the male abdomen. These consist of a ventral, trans-verse row of spines or bristles, also comblike, near the middle of the third segment, and a ventrolateral pair of tufts of long hairlike scales that appear to arise from the intersegmental membrane between segments three and four. These hairy tufts resemble coremata, but do not seem to be extensile to any great degree. These anterior ventral structures of the male abdomen may be present or absent in Melanolophiini, even sometimes between species of the same genus, and both happen to be absent in Astalotesia. The ventral comb of the third segment also occurs in some Boarmiini, which the Melanolophiini most closely resemble, but the tufts that resemble coremata, when present, are unique to the Melanolophiini, as far as we know. Although placement of the new genus Astalotesia in the tribe Melanolophiini
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