ENTOMOLOGY 209 



haunt the burrows of the bees and their larvae, and, so far as 

 known, hve on the pollen masses stored in the cells of these 

 Hymenoptera. W. W. Marchard {Monog. Rockfeller Inst. Med. 

 Res., 1 3) has a bulky contribution of over 200 pages on the larval 

 stages of the Tabanidae. A. L. Melander {Psyche, 27, 91-101) 

 gives a synopsis of the family Psilidae, and H. G. Dyar has a 

 contribution on the mosquitoes of Canada {Tr. Roy. Canad. 

 Inst., xii, 71-120). W. R. and M. C. Thompson {Proc. Ent. Soc. 

 Washington, xxiii, 127-39) write on the life-history of the 

 Tachinid Zenillia roseance. This research was carried out in the 

 South of France and forms part of a scheme for discovering 

 suitable parasites for introduction into America with the 

 object of controlling the injurious European Corn-borer. In its 

 second larval instar this parasite bores through the wall of one 

 of its host's tracheae by means of its spinose anal extremity. 

 An attachment is acquired, and the parasite is thus enabled to 

 breathe the air taken in during the inspiratory action of its host. 



J. E. Eyre {Ent. News, xxxii, 215-16) has a suggestive note 

 with regard to the rearing of Anthomyiid larvae on artificial 

 media consisting of agar jelly containing a high percentage 

 of extract of the larval food-plant. Hylemyia antiqua and 

 brassicce were reared by this means, and oviposition took place 

 on the media adopted. This method very possibly has a future 

 before it, particularly where it is desired to undertake rearing 

 experiments under strictly controlled conditions which might 

 otherwise be unobtainable. 



Hemiptera. — ^The two most notable contributions under this 

 heading deal with the Coccidae. Prof. Silvestri has edited the 

 final work of the late Gustavo Leonardo entitled Monographia 

 delle Cocciniglie Italiane (Portici, 1920, vi + 555, 375 figs.). 

 In this treatise 147 species are dealt with, and the volume is one 

 which will find a place on the shelves of all European students 

 of the family. The second work is by A. D. MacGillivray, 

 whose monograph. The Coccidce (Urbana, 111., 1921, $6-00) runs 

 to over 500 pages. The general introductory part might well 

 have been longer, and we deplore the many nomenclatorial 

 alterations that are introduced. The author recognises 120 

 new genera and includes very full tables of the major groups, 

 genera, and certain of the species. R. E. Snodgrass {Proc. Ent. 

 Soc. Washington, xxiii, 1-15) has reinvestigated the structure 

 of the mouth-parts of the Cicada and discusses the difficult 

 question of settling the homologies of these organs in the 

 Hemiptera. J. Davidson {Bull. Ent. Res., xii, June 1921) gives 

 a complete account of the life-cycle of Aphis rumicis, with 

 detailed figures illustrating the morphological characters of the 

 different types of individuals. Work along these lines is greatly 

 needed if we are ever satisfactorily to elucidate the problem of 



