41 
observation on the Asecodes issuing from the pupa shown at fig. 22, 
and through the round hole on the ventral side below the head at once 
establishes the tertiary parasitism. Very many specimens of this 
species were reared. The dates of rearing in numbers were September 
10 to 12, November 6, 1895, January 20, April 29, and July 30, 1896. 
We have found 
neither the pupa 
nor the larva of 
this species. A 
strange variation 
in habit was ob- 
served Septem- 
ber 9, 1895, and 
again in Decem- 
ber, 1896, when a 
number of speci- 
mens of this spe- 
cies issued from 
oneofthepuparia 
of a little scaven- 
ger fly, Gaurax 
anch or a. 
With this species we have a possible though unproved instance of 
quartern ary parasitism. In the closing paragraph of our consideration 
of the Dibrachys we have shown how it may become a tertiary parasite. 
In such an instance as this the Asecodes, should it be attracted to such 
a stung cocoon of Meteorus, for example, would become quarternary. 
Fig. 22.— Asecodes albitarsis: a, pupa of Dibrachys from which this para- 
site has emerged; b, adult female; c, male abdomen— greatly enlarged 
(original). 
Frontina aletiae Riley. 
This is the first of the primary dipterous parasites to be discussed. 1 
It is one of the most important enemies of the cotton caterpillar of the 
South, from which fact it derives its specific name. It was found in 
the course of the investigations of the cotton worm that this fly issues 
from puparia formed by maggots issuing from the larva and occasion- 
ally the pupa of Aletia argillacea in Georgia, Alabama, Mississippi, and 
Texas. It has been estimated at different times that the proportion of 
caterpillars killed by this species has reached 40 per cent. Its further 
distribution is stated by Mr. Coquillett to be Massachusetts, Florida, 
California, and Venezuela. It has been reared at this office from sev- 
eral different host insects. In addition to Aletia and Orgyia it has 
issued from Cerura sp., Dasylopha anguina, Halisidota maeulata, H. 
tessellata, Heterocampa manteo, and Lagoa opercularis. 
,r The writer is fortunate in presenting these few notes in having the benefit of the 
assistance of Mr. 1). W. Coquillett in the determination of the species and, further, 
the opportunity to consult the notes on habits and distribution which he has brought 
together for a monographic paper on the Tachinidae of North America. 
