11.0 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
reader interested in the minute differences that separate the maggots of 
these two genera, Sarcophaga and Tachina, which similarly affect the 
Cotton Worm, is referred to the notes. 37 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 carmate. 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 pupae of Heliothis 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 pupa, containing a moth 
fully formed, but from which the maggot of a Tachinid (?) fly was rap- 
idly pushing off the pupa 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. 
