572 BIOLOGY 01' CHALCIDIDie — HOWARD. 



of the genus Isocratus, wbicli are commonly reared from these insects. 

 The chalcidids which are perhaps most abundantly reared from plant 

 lice belong to the pteromaline genus Pachyneuron. The closely allied 

 genus Pachyerepis is, I feel sure, hyperparasitic, attacking primarily the 

 aphidiid parasites of plant lice, and the suspicion is growing in my mind 

 that the same may be the case with Pachyneuron. If this be so the ap- 

 parently anomalous host-habits of these insects which 1 have pointed out 

 (Proc. Entom. Soc. Washington, Vol. ii, pp. 105-109) are readily ex- 

 plainable. 



Only a few families of Coleoptera are parasitized by chalcidids. So 

 far as I know none have been reared from beetles of the adephagous, or 

 lamellicorn series.* In the clavicorn series the species of the family 

 CocctweZ/irfa' are frequently parasitized in larva state by the several species 

 of the eucyrtine genus Homalotylus. Hubbard has reared these i^ara- 

 sites from full grown larvce of Hippodamia convergens, while Mr. F. H. 

 Chittenden has shown me specimens which he has reared from larvae of 

 Coccinella 7iovemnotata^ Mysia imllata, and Psyllohora viylntimaculata. 



In the serricorn series the wood-boring species of the families Bupres- 

 tidw and Ptinidw — the subfamily Bostrichinw of the latter in particular — 

 are frequently parasitized b^^ chalcidids, the former by Chalcis and 

 Pteromalus and the latter principally by the species of the pteromaline 

 tribe Ghiropachides. Pteromalus and Entedon are also frequently reared 

 from the burrows of these insects, while Eurytoma is said to have been 

 reared from a Bostric'ms by Eatzeburg. Moreover, Popenoe has reared 

 species of each of the handsome eupelmine genera Gharitopus and liatze- 

 hurgia from the bostrichine Amphicerus bicaudatus (See Bull. 3, K.ans. 

 State Agric. Exper. Sta.). The ptinid subfamily Anobmuc is also para- 

 sitized by Pteromahift. The family Gioidw in this group is also rarely 

 parasitized and the peculiar little entedonine Astichus arithmeticus is 

 reared in Europe from Gis glabrafus and Ennearthron ajfine. Among the 

 phytophagous Coleoptera the Gerambycidw are occasionally infested by 

 l)teromalines, probably, however, only as hyperparasites upon some of 

 the numerous ichneumonid and braconid parasites of the insects of this 

 group, while there is a somewhat doubtful record by Katzeburg of the 

 rearing of a Eurytoma from a cerambycid burrow, and Ashmead's Eun/- 

 toma dorcaschenuv was reared by Popenoe from the burrows of Doreas- 

 chcma alternatum. I am informed, however, by Mr. Marlatt who was 

 with Prof. Popenoe at the time, that there is no certainty as to this para- 

 sitism and this Eurytoma is in my opinion likely to be a hyperparasite. 

 Concerning all these records of rearings from wood-boring larvaj, in fact, 

 there must always be the greatest doubt on account of the numerous 

 insects whicih inhabit moribund wood. Many of the records are mani- 

 festly inaccurate in their conclusions and a knowledge ot the true state 

 of affairs will be a matter of slow growth and contiiuions observation, 

 just as in an endeavor to arrive at proper conclusions con(!erning hyper- 



* Since this was written Mr. Ashinead informs me that he has reared a Eurytoma 

 from the larva of Dorcus in Florida. 



