"Platygaster solidaginis (Ashmead)

Polygnotus solidaginis Ashmead, Can. Ent., vol 19, 1887, p. 131.

Cresson, Syn. of Hym., 1887, p. 250.

Ashmead, Bull. 45, U. S. Nat. Mus., 1893, p. 307.

Polygnotus angulatus Ashmead, Bull. 45, U. S. Nat. Mus., 1893, p. 31.9.

Brues, Bull. 22, Conn. Geol. Nat. Hist. Surv., 1916 (1917), p. 540.

Female.1.40 mm. Head twice as wide as long, not emarginate behind, flattened in front, more or less oblong seen from above, distinctly wider than the thorax; occiput and vertex striate as in striaticeps but usually more finely so; cheeks convex, nearly as wide as the eyes, aciculate; projection of vertex broadly rounded, rather sharp, not extending far over the margin of the eye, its edge raised and the upper surface roughened; interocellar area finely shagreened; frons aciculate on the sides and below, with several striae above the insertion of the antennae.

Pedicel twice as long as wide, as long as joints three and four united, as wide as four; three a little longer than wide, narrower than four; five equal to four; six wider, slightly longer than wide to nine wider than six, as wide as long; ten as long as the pedicel, sharply pointed apically, the upper side slightly curved.

Thorax three fourths as wide as long, broadened and rounded anteriorly, convex above, as high as wide; pronotum aciculate; mesonotum shining, faintly shagreened on anterior half; notauli distinct on basal half, the median lobe rounded posteriorly; scutellum transverse, highly convex, polished, sparsely pubescent.

Abdomen elliptical, a little over twice as long as wide, narrower than the thorax, as long as the head and thorax united, pointed apically; first tergite strongly fluted, nearly perpendicular on the sides; dorsolateral ridges near the edge of the segment, the median area transverse, subconvex; second tergite a little longer than wide, not much narrowed anteriorly, the sides but slightly curved; tergites three to six unsculptured, equally long, united somewhat over half as long as the second; six a little wider than long, subacute.

Legs piceous; trochanters, all tibiae basally, anterior tibiae apically, and all tarsi (exthe last joint of each); yellowish. The relative length of the abdomen is variable, due to the telescoping of the terminal segments. Sometimes it is as long as the head and thorax united and at other times scarcely longer than the thorax.

Male.1.30 min. Projection of vertex somewhat less prominent than in the female; pedicel one longer than wide; third joint triangular, transverse, as wide as the pedicel, narrower than the fourth; four as long as the pedicel, widened and with a short projection below at apical third, rounded apically, not much longer than wide; joints five and six oval, one and onetimes as long as wide, narrower than four; seven to nine as long and indistinctly wider than five and six; ten as long as three and four united, pointed apically, the sides parallel nearly to the apex.

Abdomen a little longer and narrower than the thorax, not quite twice as long as wide. Wings hyaline, extending the length of the abdomen past its apex.

The coloration of the legs is variable. They may be mostly yellow (partly brown), or mostly black (partly yellow). One male has the abdomen as wide as the thorax, another as wide as the thorax and distended, as long as the head and thorax united.

Type locality. Jacksonville, Florida.

Other localities. Holly Springs, Pennsylvania; Raleigh North Carolina.

Type of solidaginis. No. 24606, U.S.N.M. The female and allotype male selected.

Type of angulatus. Cat. No. 25439, U.S.N.M. Type male selected.

Redescribed from the type series, eight females and three males. They were reared by Ashmead at Jacksonville, Florida, from Cecidomyia nebulosa Ashmead.

I have reared many specimens from black blister galls on Solidago collected in the valleys around Mount Holly Springs, Pennsylvania. The galls are numerous in June and July and the plants are spotted with them. A species of Eulophid was also reared from the galls.

The Museum contains specimens from Raleigh, North Carolina, reared April 11, 1902, from stem galls on aster and recorded in the North Carolina Department of Agriculture under Cat. No. 271.

The specimens Ashmead refers to as having been reared by Doctor Riley at Bushberg, Missouri, were really reared by Theodore Pergande and are now the types of my new species variabilis hereinafter specifically described. The specimens reared by Miss Murtfeldt from a gall on Solidago at Kirkwood, Missouri, also belongs to variabilis. "

Reference

Fouts., R,M 1924. Revision of North American wasps of the subfamily Platygasterinae. Proc. U.S.Natl. Mus. 63(15): 65. (one fig.)