1 882.] Entomology. 151 



little sluggish. Then suddenly its torpor increased, and through 

 the semi-transparent skin were seen hundreds of small white 

 parasitic larvae. In two days at the most the host was dead, having 

 perhaps partially finished its cocoon, while its entire body was 

 completely packed with the parasitic larvae or pupae, each sur- 

 rounded by a cocoon-like cell. A cross section of the host at 

 this stage showed a regular honeycombed structure. After re- 

 maining in the pupa state not longer than twenty days the Chal- 

 cids commenced to emerge by the hundreds. My friend, Mr. 

 Pergande, took the trouble to count the parasites which actually 

 issued from one Plusia larva, and, to our utter astonishment, the 

 number reached 2528! 



An interesting problem now presents itself as to the nature of 

 the cocoon-like cell surrounding each Chalcid pupa in all these 

 different hosts, from Lithocolletis up to Plusia. In the first place 

 it is no silken cocoon, as is readily shown by the microscopic 

 structure. Neither is it a membrane secreted from the general 

 surface of the Chalcid's body, for but a single wall exists between 

 two adjoining pupae. For the same reason it is notthe loosened last 

 larval skin of the parasite. But one hypothesis remains, and that 

 is that it is a morbid or adventitious tissue of the host, and this 

 the histological structure of the cell-wall seems to show, as it is 

 hyaline with a few simple connective tissue fibers running through 

 it. Serious objections can also be brought up against this con- 

 clusion; but it is a point which it will be difficult to absolutely 

 settle without closely watching the actual process of formation. 



To return to our Lithocolletis parasite. I find the following 

 note in Westwood, showing how even he was puzzled by what 

 seems to have been a very similar object : 



" De Geer has figured a minute black species with dirty white 

 legs, which he reared from minute cocoons attached together side 

 by side, found in the burrow of the larva of one of the pear leaf 

 miners. The figure has somewhat the air of an Enevrtus ; but the 

 pupae are naked in that genus. Can it be a Platygaster? or is it 

 one of the Eulophides as the antennae would seem to imply ?" (In- 

 troduction, Vol. 11, p. 170, foot-note.) 



The italics are mine and the clause is emphasized from the fact 

 that all the species to which I have referred above belong to the 

 Encyrtid genus Copidosoma, of Ratzeburg, which, at the time 

 Westwood wrote, was still included with Encyrtus. Westwood's 

 mistake was in considering the cocoon-like objects as really 

 cocoons, and this led him astray in his determination.—/:. 0. 

 Howard. 



New Insects Injurious to Agriculture. 1 — -Almost every year 

 the appearance of some insect or insects injurious to agriculture, 

 Dl *t previously unknown in an injurious capacity, has to be re- 

 | [ Abstract of a paper read at the Cincinnati meeting of the A. A. A. S., by C V 



