50 PROCEEDINGS OF THE NATIONAL MUSEUM vol.69 



very weak anteriorly, a little more pronounced posteriorly and unit- 

 ing to form an elongate polished impression that is more pronounced 

 than in erythrogaster; furrow in front of scutellum foveolate; propo- 

 deum rugulose, sometimes more or less distinctly areolated; meso- 

 pleural furrow shallow, smooth; areolet of anterior wing usually 

 decidedly petiolate; first abscissa of mediella about as long as the 

 second ; first abdominal tergite more or less longitudinally striate or 

 wrinkled and with two prominent dorsal keels ; the transverse furrows 

 on second and third tergites and the suture between the two usually 

 more or less foveolate; ovipositor sheaths about two-thirds as long 

 as the body. Head black, sometimes more or less reddish below; 

 thorax black, with propodeum and metapleura and sometimes part 

 of pro and meso pleura red; the propodeum rarely partly blackish; 

 wings infumated; anterior and middle legs mostly black or blacldsh; 

 posterior coxae, trochanters and femora red, the trochanters very 

 rarely a little fuscous in small male specimens; posterior tibiae usually 

 red, black at apex, but sometimes mostly dark reddish brown; hind 

 tarsi black; abdomen red. Length, usually about 4 to 6 mm. 



In addition to the type series the National Museum has a series 

 of six specimens, which were reared from Acrohasis, species, at 

 Brownsville, Texas, under Quaintance Nos. 16981, 16994, 16995 

 16996, 16997; and nine specimens recorded as parasitic on Acrohasis 

 caryivorella Ragonot at College Station, Texas (S. W. Bilsing) . 



24. BASSUS ERYTHROGASTER Yiereck 



Bassus (Aerophilopsis) erythrogaster Viereck, Proc. U. S. Nat. Mus., vol. 44 

 1913, p. 555. 



Type. — In the United States National Museum. 



Very close to acrobasidis, but certainly distinct, and separable by 

 the differences pointed out in the above discussion of that species. 

 In the specimens examined the antennae vary from 27 to 29 seg- 

 mented, and in the female the apical segments are usually less slen- 

 der than in acrobasidis; the parapsidal furrows are distinctly a little 

 sharper anteriorly than posteriorly, and the posterior impression 

 formed by their union is very shallow and not so well marked as in 

 acrobasidis; the propodeum is usually more or less distinctly aerolated, 

 the areas somewhat roughened; mesopleural furrow very shallow, 

 polished; metapleura smooth; areolet of anterior wing triangular, 

 usually with a very short petiole; the two abscissae of mediella 

 about equal; abdomen as described for acrobasidis; ovipositor sheaths 

 two-thirds to three-fourths as long as the body. Head and thorax 

 black, with usually the metapleura in part, and rarely more or less of 

 propodeum, red; only very rarely are metapleura and propodeum 

 entirely red; wings infumated; legs as in acrobasidis, except that the 

 hind tibiae are nearly always black; abdomen red. 



