Page:Life histories of American Cynipidæ.pdf/26

 the base of the second segment; this segment covering two-thirds of the abdomen, and somewhat produced dorsally rufous, the coxoe piceous basally, the hind coxae almost entirely piceous; hairy, hairs densest on the tarsi; tarsal claws simple. slightly tinged with yellowish, the veins light yellowish or almost colorless, except the subcostal and basal veins and the first abscissa of the radius which are light brownish yellow; areolet of moderate size or moderately large; cubitus very faint, not reaching the basal vein; radial cell open, broad; first abscissa of the radius angulate, not sharply so, without a projection into the radial cell. 2.73.7 mm.

[Redescribed from Bassett material bred from root-galls, and taken ovipositing in white oakbuds.]

—Larval cells (Fig. 27) in the scurfy bark of the roots or the basal portions of the trunks of. oaks. The cell-wall is distinct but inseparable from the surrounding bark-tissue which does not seem to have much new tissue developed, but is distorted to cover the larval cell, forming pustules about 3-4 mm. in diameter. On the same species of oak, most likely, on which futilis occurs.

In 1873 Bassett reported finding a number of wasps of an unknown species ovipositing in the buds of white oaks, which trees bore, at a later date, quantities of the galls of futilis. This alone was not sufficient evidence to warrant conclusions, for futilis is often exceedingly abundant on the majority of Q. alba trees in a region. But by 1889 he was able to report a more complete life history of the species. He had found hundreds of females which agreed with those he had bred from root-galls ovipositing in the buds of trees which later bore futils-galls in abundance and only those galls. This evidence for the relation of the root gall to the futilis-gall does not invite much doubt. The agamic form which had come from the root-galls was described as radicis.

The eggs which produce this form weie laid in the bark during July. Because of the difficulty of finding these inconspicuous, subterranean galls, little is known of the form until it emerges as an adult the following spring, from April 22 to Arpil 25 and likely later. At such times they are often found ovipositing in the buds of the white oaks, on the new leaves of which the futilis-galls will appear.

In 1895 (Proc. Ent. Soc. Washington, III: p. 261) Riley reported the rearing of futilis galls by Pergande from buds which he had observed being pricked by several females of a cynipid which Ashmead identified as Callirhytrs clavula. Riley suggested, therefore, that Bassett's observations were in error because of misidentification. On the other hand, it is to be noted that the value of Riley's record depends on the correctness of Ashmead's identification. I have carefully examined numbers of the very specimens on which Bassett based his report, and they are available to others who wish to study them. I cannot see any specific differences between the individuals bred from root-galls and those marked as "