110 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



reader interested in the minute differences that separate the maggots of 

 these two genera, Sarcophaga and TacJiina, which similarly affect the 

 Cotton Worm, is referred to the notes.^^ Mr. Hubbard has made some 

 interesting observations on the larval habits of one of these insects, 

 probably Sarcophagid, which we quote: 



" Another fly, Tachinid (?), destroys the pupa of Aletia, but appears to 

 be rather predatory than truly parasitic. Its eggs are white, elongate, 

 and longitudinally carinate. I have found them deposited upon the mus- 

 lin covering of jars containing pupae of Aletia and Heliothis, and also in 

 the field within the webbed-up leaves containing the chrysalis of Ale- 

 tia. The following notes give all that I have preserved relative to their 

 natural history. Tachinid (?) fly. Eggs laid August 9 or 10 on mus- 

 lin cover of jar No. 2, which contained several pupai of Seliothis ar- 

 migera, all covered with earth, also feeding worms of same, with frass 

 and cotton leaves, bolls, &c. Eggs hatched during the night of Au- 

 gust 11, and the maggots disappeared into the jar. Two flies emerged 

 from beneath the surface of the earth August 17. August 19, examined 

 the jars and found several pupae destroyed by the fly maggots, also 

 two or three puparia from which the flies had not yet emerged. 



"August 5. Found in the field an Aletia pui)a, containing a moth 

 fully formed, but from which the maggot of a Tachinid (?) fly was rap- 

 idly pushing oft* the i)upa covering. It rooted about with its hooked 

 jaw like a hog, and very soon had the body of the moth reduced to 

 fragments. In about three hours the contents of the moth's body were 

 transferred to that of the maggot, which rapidly increased in size and 

 pupated to-day. As I saw the maggot almost when it first began its 

 work, and it was then more than.half grown, I am at a loss to under- 

 stand how this footless grub managed to reach this pupa after having 

 been partly fed upon another pupa and on another leaf. In a search 

 made to-day in the field I found another nearly full-grown maggot, but 

 in this case there were two Aletia pupae webbed in the same leaf. The 

 maggots had already entirely eaten one of them and was feeding upon 

 the second. On August 5 I found the first specimens of this maggot, 

 but only noticed in one case that there was a second pupa of Aletia 

 webbed on the same leaf. In my breeding- vials, if several of these mag- 

 gots are confined together, and the slightest scarcity of food exists, they 

 turn upon each other. I believe the mother fly nearly always lays two 

 or more eggs together. The young maggots are thus enabled to destroy 

 very rapidly and eat the whole of a pupa, a part of which would dry up 

 if there was but one maggot. When all the food is consumed the mag- 

 gots eat each other, until but one is left. In this way a single pupa 

 will suffice for a maggot, because there is no waste. In the field these 

 maggots are becoming more numerous, but are not by any means 

 abundant. 



