A Miocene Wasp

Abstract

IN NATURE of June 13, 1901 (vol. lxiv., p. 158), I described a curious variation in a bee (Epeolus), the second transverso-cubital nervure of the wings having its lower half absent. This aberration was evidently an example of “discontinuous variation,” and from its occurrence in several specimens captured at the same place, it seemed that it must be inherited. There is a genus of Scoliid wasps, Paratiphia, in which the absence of the lower part of the first transverso-cubital nervure is normal. The species, found principally in the southern and western parts of North America, are quite numerous; and the broken nervure, looking exactly like the aberration described in the bee, is a good generic character. Nothing has hitherto been recorded concerning the past history of this genus, but, I have before me a well-preserved Paratiphia from the Miocene shales of Florissant, Colorado, collected by Mr. S. A. Rohwer at station 14 in 1907. This insect, which I shall call Paratiphia praefracta, is black, with the thorax large and robust (about 4 mm. long and 31/4 mm. broad); the head rather small (slightly more than 2 mm. diameter); the antennæ thickened; the abdomen constricted between the first and second segments, and parallel sided beyond; the hind tibiæ dentate on the outer side; the wings clear hyaline, anterior wing about 7 mm. long, with, the large stigma very dark, the nervures light ferruginous. The specimen is a male. The venation is perfectly, normal, for Paratiphia in every respect, including the broken transverse-cubital vein.