20 MISC. PUBLICATION 241, U. S. DEPT. OF AGRICULTURE 
ton, Va., August 14, 1916, from P. vittata; 7 labeled “‘Bred from Phyl- 
lotreta, Aug. 20, 09, Arlington, Va., Smyth and Jones Coll.”’; 7 from 
P. vittata, Washington, D. C., August 9, 1906; and 1 from the same 
host, Baton Rouge, La., November 10, 1931. This material exhibits 
some color variation, the thorax sometimes being mostly piceous and 
the abdomen more or less piceous beyond the first tergite. The 
antennae are nearly always 19-segmented, as in the type, rarely 18- 
or 20-segmented. 
(8) MICROCTONUS PUSILLAE, new species 
_Exceedingly like vittatae, from which it differs, however, in its 
slightly shorter malar space, smooth and nearly bare middle lobe of 
mesoscutum, the presence of a distinct median longitudinal carina 
behind the middle lobe of the mesoscutum, and the, usually, relatively 
shorter first abscissa of radius. Both sexes occur, while in vittatae 
only females are known. | 
Female.—Length about 1.5mm. Agrees with description of vittatae except as 
follows: Malar space slightly shorter than basal width of mandible; antennae 18- 
segmented; middle lobe of mesoscutum smooth and practically bare, the pubes- 
cence restricted to a few scattered hairs anteriorly; propodeum not smooth and 
shining at base each side of middle; first abscissa of radius much less than half as 
long as width of stigma; lower abscissa of basella about as long as nervellus. 
Male.—Mucbh darker in color than female, the head except mouth region entirely 
black, thorax entirely black or blackish and abdomen mostly piceous; antennae a 
little longer than body, 22-segmented; propodeum a little smoother at base than 
in female; temples and cheeks fully as broad as eyes. 
Type locality — Rocky Ford, Colo. 
Type.— United States National Museum no. 49911. 
Host.—Phyllotreta pusilla Horn. 
Described from 11 females and 12 males reared by H. O. Marsh, of 
the Bureau of Entomology, June, July, and August 1916, under 
Chittenden nos. 3133 and 3134. The female paratypes vary in 
color as in vittatae; the antennae of the female are nearly always 18- 
segmented, rarely 17-segmented; those of the male paratypes have 
from 21 to 23 segments. The National collection contains also 7 
field-collected specimens from Idaho; these are not included in the 
type series. This is the species referred to by Chittenden and Marsh 
(3, p. 13) under the name Perilitus epitricis Viereck, in their discussion 
of Phyllotreta pusilla, the western cabbage flea beetle. 
The Genus WESMAELIA Foerster 
Wesmaelia Foerster, Verhandl. Naturh. Ver. Preuss. Rheinlande 19 (N. F. 9): 
251, 1862. (Genotype, Wesmaelia pendula Foerster.) 
Head large, although hardly subquadrate, completely margined behind; eyes 
prominent; antennae slender, the scape short; notauli impressed; posterior face of 
propodeum long, rather abruptly declivous and broadly excavated down the 
middle; legs slender, coxae very small; medius weak; two cubital cells; first cubital 
and first discoidal cells separated; radial cell at least no longer than stigma; 
second abscissa of radius curved; recurrent vein nearly interstitial with inter- 
cubitus; first abdominal segment unusually long and slender, about twice as long 
as posterior coxa and trochanter combined, and but little broader than high, not 
carinate at sides, slightly thickest at the spiracles, which are at about the middle; 
remainder of abdomen subcompressed; second and third tergites fused, occupying 
pues of dorsum of abdomen and overlapping beneath; ovipositor sheaths exserted, 
ut short. 
In the writer’s opinion there is but one known species of this genus, 
although it has been described under four different names, twice from 
Europe, once from the United States, and once from Asia (Turkestan). 
