MONOGRAPH OF THE NOETH AMERICAN PROCTOTRYPID.E. 345 



Tlie short 3-Joiiited maxillary palpi and the subdei)res,sed smooth met- 

 athorax distinguish this genus from Provtotrypes and Disogmiis. No 

 species is known from North America. 



Subfamily IX.— BELYTIN^. 



Head transverse or subglobose. Ocelli 3, in a triangle, rarely want- 

 ing. Eyes most frequently hairy. Mandibles usually short, acute at 

 tips, with a tooth within, rarely falcate and crossing each other at tips. 

 Maxillary palpi 4- or 5 jointed; labial palpi 3-jointed. Anteuuie por- 

 rect, inserted on a frontal prominence, in males 14-jointed, in females 

 14- or 15-jointed, filiform setaceous, or subclavate, or more rarely 

 clavate-moniliform, the scape long. Prouotum distinctly visible from 

 above and narrowed into a .short neck at the junction with the head; 

 mesonotum usually as broad as long, with deep furrows, rarely entirely 

 without furrows; scutellum convex, deeply foveated at base; meta- 

 thorax short, usually carinated, rarely spined, posteriorly truncate 

 or emarginate. Front wings with a closed costal cell, a single basal 

 cell, and a radial or marginal cell, the latter either closed or open, with 

 a branch of a vein interstitial with the second abscissa of the radius 

 and extending backwards into the discoidal field of the wing; it is 

 quite rare for the marginal cell to be entirely wanting ; hind wings always 

 with abasal cell. Apterous forms rare. Abdomen distinctly petiolated, 

 oblong-oval, ovate, conic-ovate, or pyriform, and composed of from 3 to 8 

 segments, the second segment always large. Legs rather long and 

 slender, the tibial spurs 1, 2, 2, the tarsi long, slender, 5-jointed, claws 

 simple. 



An extensive and but slightly studied group, closely related to the 

 Diapriiuce and formerly confused with them. A Belytid may, however, 

 always be distinguished from a Diapriid by having a distinct basal cell 

 in the hind wings, and by the 3-jointed labial palpi; also, except iu a 

 few cases, by the venation of the front wings, which have a distinct 

 basal cell and usually a distinct marginal cell. 



The exotic genus Mo)iomachusWei>twoodj at present placed with the 

 Evaniida', should i^robably be placed in this group; but as the genus 

 is known to me only from the description I can not tell positively with- 

 out seeing specimens for study. 



Nothing is known of the habits of the species composing this group, 

 although Nees von Esenbeck and others believe they undergo their 

 transformations within the larv?e of Diptera that inhabit fungi. From 

 their close structural resemblance to the Proctotrypimc this supx^osi- 

 tion is probably correct. 



Our entomologists should give more attention to the rearing of 

 insects infesting fungi, not only for the purpose of throwing light upon 

 the obscurity that en veils these insects, but upon those of other groups, 

 and it is hoi)ed the near future will bring forth some results from those 

 so situated as to make observations upon fungi-feeding insects. 



