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DIPTERA. 45 
body in some individuals is without markings, while in most it is dis- 
tinctly marked with dark cross bands on the back in the middle of the 
joints, while at each side is a white space; the under side is more or 
less irregularly spotted with brown. 
The head is yellowish brown, nearly square, horny, and marked as 
in the figure (fig. 10). 
Qdaneboee 
Fic. 10.—Simulium pecuarum: head of larva—a, beneath; b, side; c, above—greatly enlarged (from 
Annual Report Department Agriculture, 1886). 
The tip of the abdomen is crowned with rows of hooks (see fig. 11) 
and on the upper side of the abdomen is the set of breathing organs, 
which have been mentioned heretofore. 
The larve are found more particularly attached to submerged 
logs, wholly or partly submerged stumps, brush, bushes, and other like 
objects in the larger creeks and bayous of the region to which they are 
common. 
They cluster together, and, fastened by the posterior protuberance to the leaf, they 
assume an erect position, or make their way upward and downward with a looping 
gait. Frequently attached by a minute thread, they sway with the ripples at or 
near the surface of the water, often as many as half a dozen being attached toa 
single thread. * * * They make their way up and down these objects with 
perfect freedom, but do not venture above the water. 
Food of the larvea.—The larvez of the Southern buffalo-gnat are carnivorous in their 
habits, although they do not, perhaps, reject floating particles of a vegetable origin. 
Their mouth is not adapted for biting off any pieces 
from a large or solid substance, but 1s constructed to 
catch and ingulf small objects. To obtain these the 
fan-like organs peculiar to these larve create currents 
of water directed toward the month. Anysmall and 
floating matter drifted by the current of water into 
the vicinity of these fans is attracted by the ciliary 
motions of the component rays of the same, and thus yh ; 
Fig. 11.—Simulium pecuarum: Tip 
reaches the space embraced by them, and they, bend- of abdomen—enlarged (frean Am 
ing over the mouth, direct the further motions of the nual Report Department Agri- 
particles. If of the proper kind they are eaten, other- culture, 1886). 
wise they are expelled by a sudden opening or parting 
of the fans. They do not feed, as has been claimed, upon plants which they are 
unable to bite off or chew, and which do not exist in the water at the time when the 
larvee grow most rapidly. A searching investigation of the water in their breeding 
places revealed the fact that it was swarming with animal life, and was filled with 
the larval forms of small crustaceans belonging to various families, but chiefly to 
those of Copepods and Isopods. An abundant supply of food must also be found in 
