ART. 23 REVISION OF MACROCENTRUS MUESEBECK 27 



half its length; mediella much more than twice the length of lower 

 abscissa of basella, the latter not distinctly as long as nervellus. 



Abdomen longer than head and thorax combined, very slender, 

 not half as wide as extreme width of thorax ; first tergite more than 

 twice as long as broad at apex, longitudinally striate, its spiracles 

 before end of basal fourth; second tergite longer than broad, com- 

 pletely aciculate, the lateral depressed margins very narrow, not 

 wider at base than at middle of tergite ; third tergite about as long 

 as broad, aciculate on basal two-thirds; ovipositor sheaths very 

 slightly longer than the body. 



Entirely testaceous except for a weak suggestion of infuscation 

 at apex of propodeum, at base of first tergite, and on apical ab- 

 dominal tergites; antennal flagellum usually fuscous, the scape and 

 pedicel pale yellow; legs mostly testaceous, posterior coxae infus- 

 cated apically above; wings hyaline, veins and stigma brownish, 

 the latter with a pale spot at base. 



Type.—U.S.^M. No. 43502. 



Type locality. — Bentonville, Ark. 



Host. — Canm'sm sp. 



Remarks. — Described from three female specimens reared in the 

 Bureau of Entomology by D. Isely, July 20, 1918 (type), July 21, 

 1918, and June 18, 1919 (paratypes), the type and first paratype 

 under Quaintance No. 16392, the second paratype under Quaintance 

 No. 16472. 



17. MACROCENTRUS INSULARIS, new species 



Most closely related to canarsiae, but distinguished by the char- 

 acters given in the key. 



Female. — Length about 7 mm. Face broad, sparsely punctate ; eyes 

 large, prominent ; malar space hardly as long as basal width of man- 

 dible; clypeus about as broad as half the width of face; mandibles 

 stout; ocell-ocular line about one and one-half times as long as 

 diameter of an ocellus; maxillary palpi long, the longest segment 

 distinctly longer than second segment of antennal flagellum; apical 

 segment of labial palpus nearly as long as the two preceding seg- 

 ments combined; antennae 54-segmented. 



Thorax rather stout; notauli foveolate behind, propodeum finely 

 rugulose; mesopleura and metapleura mostly smooth, with some 

 scattered shallow punctures; apical teeth of all trochanters well de- 

 veloped; radius arising from distinctly beyond middle of stigma; 

 radial cell rather short, the metacarpus extending the length of second 

 intercubitus beyond apex of radial cell ; nervulus postf ureal by about 

 half its length; submedian cell sparsely hairy apically; mediella 

 much more than twice the lower abscissa of basella, the latter hardly 

 as long as nervellus. 



