PARASITES OF ALETIA. 



101 



during the past five years that the Boll Worm {Reliothis armigera) Tvhen 

 approaching full growth develops a strong, carnivorous appetite, and 

 not only destroys the 

 smaller worms of its own "^^SM^^-^ \ 

 species, but also enters ^^^™^^^^^ 

 the loose cocoon of the 

 Cotton Worm and feeds 

 upon the inclosed pupa. 

 There is good evidence 

 that the Grass Worm 

 {Lapliygma frugiperda) 

 occasionally eats the Cot- 

 ton Worms, a fact which 

 seems probable from the 



known habits of La- YiG.dO.—Libellulatrimaculata. (After Sanborn.) 



phygma, and even the Aletia larva, like many other species of its order, 

 when hard pressed, will develop cannibal propensities. 



PARASITES. 



Up to the time of the appearance of the first edition of this work in 

 January, 1880, or rather up to the time of the appearance of a prelim- 

 inary article by us in the Canadian Entomologist iov September, 1879, no 

 parasites of the Cotton Worm had been recorded by name so as to be rec- 

 ognized by entomologists, and the belief was quite general that Aletia 

 was entirely free from parasitic checks. This belief, as we have already 

 seen, was used by Mr. Grote as an argument in favor of the arrival of 

 Aletia de novo from some foreign country whenever it appears with us. 

 The fact remains, however, that one of the most important of these par- 

 asites had been mentioned without name by six writers at least, and 

 that two tolerably good figures of the species had been published. In- 

 deed, the very fact of the existence of such a parasite had been used by 

 Dr. Gorham to found a theory similar to Mr. Grote's, as we shall show 

 under the head of " History of the literature." 



The following species have been discovered since we began this Cot- 

 ton Worm investigation. The observations of the past two years have 

 added four parasites to those published in the first edition of this work : 

 Infesting and issuing from the ^gg: 



(1.) Trichogramma pretiosa Eiley. 

 Infesting and issuing from the worm (the parasitism of JS'o. 5 doubtful) : 



(2.) Apanteles aletice Eiley. 



(3.) Euplectrus comstocMi Howard. 



(4.) Sarcophaga sarracenke Eiley. 



(5.) Cyrtoneiira stahulans Fallen. 



(6.) Tachina aletice Eiley. 



(7.) Tachina fraterna Comstock. 



