Spalangia attae Burks 1969

Tex.; El Salvador.

Occurs in debris of nests of Atta mexicana (Smith) and A. texana (Buckley).

Spalangia attae

This species agrees with Spalangia drosophilae Ashmead in being small, less than 2.0 mm long, with the thorax depressed and flat, in lacking the crossline of punctures near the posterior margin of the pronotum, in having the frenal crossline of the scutellum indicated only at the lateral margins, and in having closely set, longitudinal striae on the mesopleuron. The two differ in that attae has the head and pronotum shagreened and mat rather than smooth and shining with scattered punctures; the petiole is as long as the hind coxa, rather than being shorter than the hind coxa; and the foretarsal segments are markedly shorter in attae than they are in drosophilae (Figures 2, 3).

FEMALE.—Length 1.5 mm. Black, with basal 4 segments of each tarsus white, apical segment brown; tegulae brown, wing veins tan. Surface of head minutely shagreened and mat, except for ocellar triangle, which is smooth, antennal scape closely and irregularly sculptured, dull; pronotum, except for narrow, smooth crossband at posterior margin, minutely shagreened and mat; scapulae shining; praescutum shining at anterior margin, elsewhere with minute, contiguous and shallow pits in transverse, closely set rows, these becoming irregular near posterior margin of sclerite; axillae, scutellum, and postscutellum smooth and shining; metepisternum minutely shagreened and mat; propodeum shining; petiole with numerous, closely set, longitudinal carinae, interstices with minute cross septa; surface of gaster shining. Anterior coxae sub-shining, with minute, closely set, parallel striae; middle coxae reticulated at bases, smooth and shining apically; hind coxae smooth and shining. Prepectus heavily and irregularly sculptured. Mesopleuron with lineolate sculpture dorsally and near base of midcoxa, pitted sculpture in anterior oblique impressions and in 2 oval impressions posteriorly, elsewhere smooth.

Eyes and head hairy, but head hairs not arising from obvious punctures (these obscured by the shagreenate sculpture); distinct groove extending from anterior ocellus into apex of scrobe cavity; malar furrow almost hidden by head sculpture; length of malar space equal to eye height. Relative lengths of parts of antenna, scape 55; pedicel, 20; first funicular segment, 8; second, 5; third, 6; fourth, 7; fifth, 7; sixth, 8; seventh, 8; club, 25.

Dorsum of thorax depressed and flat, as in drosophilae Ashmead. Pronotum bearing numerous bristles, but punctures from which they arise obscured by shagreened surface sculpture; crossline of punctures wanting near posterior margin. Notaulices and lateral margins of scutellum with crenulate sculpture; margin of scutellar frenum indicated only by 2 punctures at each lateral margin; posterior margin of scutellum crenulate, setting off postscutellum. Foretarsal segments compact, first segment as long as following three combined (Figure 2); middle and hind tarsi slightly more elongate.

Propodeum with crenulate anterior and lateral margins, a double row of coarse, rectangular punctures on meson. Petiole stout, half as wide as long, and as long as hind coxa. Gaster as long as thorax and propodeum, apical sternite (subgenital plate of Snodgrass) produced as a minute point on meson, not indented, as in drosophilae; apices of ovipositor sheaths slightly exserted.

MALE.—Unknown.

TYPE-LOCALITY.—Near San Salvador, E1 Salvador.

HOLOTYPE.—USNM 69871.

Described from a single specimen from debris of a nest of the leaf-cutter ant, Atta mexicana (F. Smith), 25 June 1958, by O. L. Cartwright. The host of this Spalangia is not known, but it should be some small dipteron. It was taken along with a large assortment of beetles, including staphylinids, scarabaeids, tenebrionids, and others (the collector is a Coleopterist).

I have another specimen of this Spalangia, unfortunately badly broken, that was taken from a nest of Atta texana (Buckley) at San Antonio, Texas, 16 January 1935, by E. V. Walter. It was collected in the ant nest at a point seven feet below the surface of the ground. I have not designated this specimen a paratype because it is fragmentary.