42 Bulletin Wisconsin Natural History Society. [Vol. 10, Nos. 1 & 2. 
fifth and last lot of 148 cocoons taken from a single host larva, 
there emerged 93 Apanteles, 15 Mesochorus, and 23 viridescens. 
Of the total number of 935 cocoons of Apanteles congregatus 
(Say), or of that number of larvse successfully coming to full 
growth on five host larvae, but about 258 or 27.5,%' survived to 
maturity. Other rearings of the species are as recorded in the 
foregoing. 
Habits of the Species 
The manner of emergence of this parasite from the cocoons 
of Apanteles congregatus (Say) is ably described by Fitch as 
follows: 
“And after these flies have left their cocoons, it is readily told by 
the appearance of each cocoon whether it is a Microgaster or a Ptero- 
malus fly which has come out from it. The Microgaster, by which all 
the cocoons are constructed, makes an opening- for its 'escape in a 
more neat and artistic manner than does its destroyer. ******** 
The enclosed fly then pressing- its head against the lid raises it up 
and crawls forth from its prison. Thus the evacuated cocoon has its 
end smoothly cut off with the severed portion usually adhering to* it. 
The Pteromalus fly, on the other hand, being a size srrtaller, is able 
to move about and can probably turn itself around inside the cocoon. 
And to make its escape, it gnaws a hole through the side near one 
<?nd, of sufficient size for its body to pass through, this hole in differ¬ 
ent instances being round, oval, or irregular, and its edges ragged 
and uneven.” (Page 228). 
In regard to the habits of the adult, Fitch has the following 
to say: 
“This insect, ************** appears tame and sedate, 
walking around slowly, and as if with deliberation as to what it is 
doing; and if any annoyance approaches it, to escape therefrom, it 
gives a slight skip, throwing itself about an inch, and repeating this 
leap again and again if pursued, it being not at all inclined to take 
wing.” (Page 227). 
Further than what is known concerning its host relation, and 
the few observations quoted from concerning its habits, but very 
little else of importance is known concerning the biology of the 
species. 
It hibernates in the cocoons of its hosts as indicated by the 
records of rearings given in the foregoing and what is stated by 
