123 
DIPTEROUS PARASITES — TACHINID^. 
There are a number of species belonging to this family of flies 
which are parasitic on the bollworm. The female fly deposits her 
eggs on the surface of the body of the larva, generally toward the 
anterior end. Sometimes but a single egg is laid, although a parasi- 
tized larva frequently bears several eggs attached to it. The eggs are 
of a pearly white color when first laid, but often turn darker when the 
embryo begins to develop in them. They are somewhat less than a 
millimeter in length, elongate in shape, with rounded ends and paral- 
lel sides. As soon as the egg hatches, the parasitic grub bores into the 
bollworm through the skin and begins feeding upon its fatty tissue, 
undergoing a very rapid growth. Even when a number of eggs are 
attached to a single larva, it is rare for more than one parasitic grub 
to mature in the bollworm. 
The species of the family resemble each other so closely that it is 
almost impossible for anyone not familiar with them to recognize the 
different forms. The table below gives a summary of the species bred. 
Table XLIX. — Species of Tachinidx bred from holhvorms during 1903 and 1904. 
Name. 
Locality. 
Date. 
Food plant of 
bollworm. 
Winthcmict It-ptistuldto, Fab 
Paris Tex 
Aug. 22,1904 
Sept. 4,1903 
Aug. 18,1904 
Nov. 2,1904 
Nov. 7, 1904 
May 26,1903 
May 29,1903 
Alfalfa 
Calvert, Tex 
Euphorocera claripennis Macq . . 
Paris, Tex 
Ladonia Tex 
Alfalfa 
Gonio, ccvpitdid De G 
Do 
Do 
Paris, Tex 
Do. 
Archytas piliventris v. d. W 
Victoria, Tex 
Com 
Do 
do 
Do 
Of these it is probable that the first is most valuable in northern 
Texas, and the last mentioned (see fig. 25) in the southern part of the 
State. 
In addition to this list the following 
species are known to be parasitic on the 
bollworm, although they were not bred 
by us during the past two seasons: 
Frontina arinigera Coq., F. frenchii 
Will., and F. aletlm Riley. The first 
was bred b}'- Coquillett^ from boUworms 
collected at Los Angeles, Cal. ; the second 
b}' Rile}^^, and the last by Trelease^. 
Early in November a lot of eighty- 
seven larva3, mostly full-grown, were ^ „, , , ., . . , ^ 
' X P ' YiG. 25.— Archytas pthventris: adult fly 
collected b}^ Mr. Girault in an alfalfa (original). 
field at Paris, and forty of them, or nearly 50 per cent, bore tachinid 
fly eggs on their bodies. One had as many as eleven, but most of 
« Insect Life, J, p. 331. 
^Fourth Missouri Kept. p. 129, footnote. 
•Fourth Eept. U. S. Ent. Com., p. 377. 
