116 
parasite (Fig. 59, Plate 15) is a wasp, and is also shown upon 
the plate, greatly enlarged; its natural size is indicated by the 
lines near it. | 
The adult flies, about ,, of an inch long, are of a pale yel- 
lowish-green color. The large head is marked with a triangu- 
lar black spot at base, inside of which are located the three 
simple eyes; the large compound eyes possess in life a beautiful 
bronze color. The thorax is marked with three longitudinal 
bands; the abdomen is also ornamented with three longitudinal 
bands, which are interrupted at the sutures, but more or less 
confiuent toward the posterior end. The color of the under- 
side of the fly is uniformly yellowish-green, excepting two tri- 
angular spots upon each side above the posterior and middle 
coxe. The legs partake of the same general color; the thighs 
are slightly darker, and the tibize and tarsi dusky. The hind 
pair of thighs are very much swollen, and are provided on the 
under surface with two rows of small spines. The hind tibize 
are very strongly curved. The two large basal joints of the 
antenne are yellowish. 
The eggs of the American Meromyza are glistening white, 
with longitudinal ridges, the space between the ridges is faintly 
reticulated. They are very elongated, being .023 of an inch 
long and .005 of an inch broad. 
The larva or maggot is very pale green and very slender, 
being about one-fourth of an inch long by one thirty-second of 
an inch wide. Its head is provided with a pair of black toothed 
hooks. The covering of the apparent pupa is simply the 
shrunken larval skin, which protects the true pupa forming 
inside. As soon as the real pupa is formed it becomes visible 
through the transparent larval skin, and is seen to be also of a 
pale green color. It is about one-sixth of an inch long and 
about one-thirtieth of an inch broad. As the imago is formed 
inside the pupa, the eyes, wing-pads and legs become appa- - 
rent. 
Some of the adult flies were sent to Prof. F. M. Webster for 
comparison. Hesays: ‘I amagood deal puzzled. The flies 
do not look exactly alike (like Ohio specimens), yet do not vary 
more than we might expect, considering distance and latitude 
that have separated Minnesota specimens from eastern ones. 
The method of attack by the larve is exactly the same, i.e., 
