H Y ME NOP TERA 921 



other parasites. A few species are inquilines, but none has been 

 found to be injurious to vegetation. 



The North American Proctotrupoidea were monographed by 

 Ashmead ('93). Note that the first three subfamilies of Ashmead's 

 classification, those in which there is an anal lobe in the hind wings, 

 are not now included in the Proctotrupoidea. 



The Proctotiaipoidea is represented in our fauna by nine families ; 

 these can be separated by the table of families on pages 906 to 915. 

 A list of these families follows. 



The family ROPRONIID^ is represented by a single genus, 

 Ropronia, which includes a small number of rare species, the habits of 

 which are unknown. 



The family HELORID^ includes the genus Helorus, the larvee 

 of which are parasitic in the cocoons of Chrysopa. 



The family VANHORNIID^ includes a single rare species, 

 Vanhornia eucnemiddnim, which is parasitic on larvee of beetles of 

 the family Eucnemida? and has been found in New York, Maryland 

 and Virginia. See Crawford ('09). 



The family BELYTID^. — Some species, at least, are parasitic 

 in the larvae of Diptera. For a monograph of the family see Kieffer 

 ('16). 



The family PROCTOTRUPID/E.— Parasitic on dipterous and 

 coleopterous lar^^ae. For a monograph of th? family see Kieffer ('14). 



The family CERAPHRONID^.— Some of the species, at least, 

 are parasitic on aphids and cecidomviids. 



The family SCELIONID.^.— This is a very extensive family and 

 one of great economic importance. The species are egg-parasites, 

 infesting the eggs of practically all orders of insects and the eggs of 

 spiders. 



The family PLATYGASTERID^.— Parasitic in the larvae of 

 Cecidomyiidag and Tipulidas. 



The family PELECINID^.— This family is represented in our 

 fauna by a single species Pelectnus polyturdtor, which is a very remark- 

 able insect . Th e fe- 

 males are common 

 where they occur 

 and are easily rec- 

 ognized by the 

 slender and long ab- 

 domen (Fig. 1 1 59). 

 The abdomen of the 

 male is club-shaped 

 and only about 

 twice as long as the 

 head and thorax. Fig- ii59- 



This sex is very 



rare in this countr}' but is common m some parts of South America; 

 it can be recognized by the venation of the wings, which is similar to 

 that of the female. This species is parasitic on the larvae of May- 

 beetles. 



