AMERICAN ITYMENOPTERA. 57 



IV. — On some .species of Callimome, parasitic on galJs. 



The nuiuerous parasites infest'm<; the galls of Cijnipidfe and Ccciilo- 

 myix^i afford a most interesting aud yet entirely unexplored field of re- 

 search. IJesides the inrjuilinous Ci/nipid,ie,, like Aidux, Cnroptres^ 

 Sj/>icr(ji(s, a large number of other insects is obtained by those who 

 collect galls for the purpose either of preserving them, or of rearing 

 the gall-produeing insect. Most of those belong to the family of Chal- 

 cidiiliv, and especially to the genera Ca/limome, Onni/rux, Eunjtoma 

 and Decdtonia. Here and there species of Pteroinaliis, l^e/nisfichiis, 

 or a wingless Enpi'hnus are obtained. That the economy of gulls is 

 not confined to llymenoptera alone, is proved by the fact that more 

 than once I have obtained a Coleopteron, Hjjdiiocc.ra verticalis, from 

 galls in my breeding-boxes, (compare Proc. Ent. Soc. Phil. 1861, pp. 

 68 and 71). The curculio O/idocepha/us amcricanns also occasion- 

 ally takes its abode in the coiky substance of a gall, (compare 1. c, 

 P-6S). 



Various are the relations in which all these species stand to the 

 gall-producing insect, and it is in this direction that a great deal re- 

 mains to be observed and studied. It seems that while the inquilinous 

 or parasitical Ci/nipidx (^Aulax, Synerr/tis, etc.,) live in the gall with- 

 out attacking, although probably often injuring, the gall ]»roducing 

 equips, the Chalcididse are real parasites, the larva; of which live afc 

 the expense of the larva of the gall-producer. But here, again, the 

 questions how and when the eggs were deposited, what influence the 

 parasites have on the growth of the gall, what difference exists be- 

 tween the mode of life of a Callimome and an Onnjrus or some other 

 genus — all these questions remain unanswered. 



My purpose in the present paper is merely to describe a few species 

 of Callimome, obtained from galls by me or by others. I have con- 

 fined myself to the most striking forms, omitting a good many species, 

 which, from want uf well defined plastic characters, I could not suffi- 

 ciently characterize. 



Species of Callimome are obtained from galls both of C;/ni]>idii and 

 Cecidomjiit., and hence, although the series of papers to which the 

 present one belongs, treats of the natural history of the (\i/iiij,ld-rr only, 

 I could not well omit the mention of those species of Callimome which 

 infest the galls of (.'ecidomi/ia. In one case (C advrua^, it seems 

 pretty certain that the same species was bred from the galls of a Cj/- 

 nips and of a Cecidomi/ia. 



If, on one side, the same species of Callimome infests galls of differ- 



THAXS. AMKR. KST. SOC. (8) UAUCII, 1S70. 



