38 PROC. ENT. SOC. WASH., VOL. 24, NO. 2, FEB., 1922 



parasitic relatives, probably originally parasitic upon some 

 internally feeding larva, frequently one living within a gall, or 

 possibly a seed or a grass stem. More than likely in every 

 instance the host larva lived in some such circumscribed 

 position where not only its movements were restricted but its 

 food confined to a particular kind of plant tissue. The para- 

 site larva attacking such a host externally would be in direct 

 contact with the plant food of its host. Feeding as it would 

 upon a larva whose food was restricted to a particular kind of 

 plant tissue, the food of the parasite would consist of the same 

 material after it had undergone digestion and assimilation by 

 the host. Just how great would be the chemical changes 

 involved in these processes is of course unknown. In the case 

 of an insect larva they would probably be relatively simple as 

 compared to those of higher animals. The nutritive require- 

 ments of the parasite doubtless approximate chemically those of 

 the host especially if the two be closely related as host and para- 

 site sometimes are. Be this as it may, the fact is established 

 that some insects are capable of accomodating themselves to 

 a degree to either animal or vegetable food. Examples of this 

 are found among Meloi'd beetles which live parasitically in 

 bees' nests, their young larvae first destroying the bee egg and 

 then feeding upon the vegetable contents of the cell. Canni- 

 balism is by no means an uncommon occurrence among certain 

 plant feeding Lepidoptera. Among Hymenoptera, the Ichneu- 

 monid, Grotea anguina Cresson has been shown to live parasiti- 

 cally in bees' nests destroying first the egg or young larva of the 

 bee and then feeding upon the bee bread. (Graenicher, Ent. 

 News, vol. 16, 1905, p. 44.) That certain species of Chalci- 

 doidea can and do develop partly as parasite and partly as plant 

 feeders has just been shown. 



Partial phytophagy probably was first forced upon the para- 

 site by premature exhaustion of the natural food supply due 

 to attacking a host which was insufficient in itself to furnish 

 food for complete development. The transition from such a 

 habit to that of development entirely as a plant feeder does 

 not appear as such a difficult matter after all. 



SPECIES CATALOG OF PHYTOPHAGOUS CHALCIDOIDS OTHER 



THAN THE FIG INSECTS. 



Following is a list, compiled from literature, of the species 

 of Chalcidoidea said to be phytophagous, omitting only the fig 

 insects, Agaonidae and Idarinae. Only those species are 

 included which have been expressly stated to be plant-feeders 

 or probably plant-feeders. Records such as "reared from 

 galls" or "reared from stems" have been disregarded unless 

 the author has definitely indicated that the species was probably 



