
A CHAPTER ON FLIES. 591 
larva is remarkable for having the abdominal segments di- 
vided into two portions, the hinder much smaller than the: 
anterior division, and its whole length is .86 of an inch. 
The pupæ were found sticking out in considerable numbers 
from the tree, being anchored by the little spines at the tail. 
The head is square, ending in two horns, and the body is 
straight and covered with spines, especially towards the end 
of the tail. They were .20 of an inch in length. The last 
of June the flies appeared, somewhat resembling gnats, and 
about .10 of an inch long. The worms continued to infest 
the tree for six weeks, the flies remaining either upon or 
near the tree. 
We now come to that terror of our equine friends, the 
Horse-fly, Gad, or Breeze-fly. In its larval state, some 
‘species live in water, and in damp places under stones and 
pieces of wood, and others in the earth away from water, 
where they feed on animal, and, probably, on decaying mat- 
ter. Mr. B. D. Walsh found an aquatic larva of this genus, 
which, within a short time, devoured eleven water snails. 
_Thus at this stage of existence, this fly, often so destruc- 
= tive, even at times killing our horses, is beneficial. We have 
found a larva (PI. 12, fig. 4), which is, probably, a young 
Horse-fly, living in abundance on the under side of the stones 
ina running brook, at Burkesville Junction, Va. The body 
was smooth, over two inches in length, and with a few fleshy 
filaments at the tip. Each segment is enlarged posteriorly, 
aiding the creature in moving about. During the hotter 
parts of summer, and when the sun is shining brightly, 
thousands of these Horse-flies appear on our marshes and 
inland prairies. There are many different kinds, over one 
hundred species of the genus Tabanus alone, living in North 
America. Our most common species is the * Green-head,” or 
Tabanus lineola Fabr. (P1.12, fig. 5 ; from Tenney’s Zoology )- 
When about to bite, it settles quietly down upon the hand, 
face or foot, it matters not which, and thrusts its formidable 
lancet jaws deep into the flesh. Its bite is very painful, as 
