BLACK-FLIES. 173 
body, bulging thorax, eleven-jointed feelers, of which the 
first two are separated from the rest; the broad abdomen is 
rather short; the legs are powerful with broad tarsi; the 
wings are broad and short. The body of these insects is in- 
vested with a fine downycovering; the males are darker and 
more velvety, and possess broader and more hairy legs than 
the females. The mouth-parts are very curious, and Prof. 
J. B. Smith has demonstrated that the female, which is the 
only one that sucks blood, possesses beside the usual sucking 
organs, genuine biting mandibles. | 
These small flies breed in rapidly flowing water, hence 
are very numerous in the northern part of our state where 
streams abound. The adult flies are well-known tormenters, 
and occur sometimes in such numbers as to prevent travel. 
Prospectors, and surveyors, though usually thick-skinned 
by living constantly out of doors, have been repeatedly 
forced to leave a region thus infested. They even force the 
Labrador fishermen to the coast in summer, as it is impos- 
sible to live in the interior on account of these tormenters. 
Prof. A. S. Packard, in ‘‘Our Common Insects,” relates his 
experience in the following words:—‘During a summer resi- 
dence on this coast, we sailed up the Esquimaux River for 
six or eight miles, spending a few hours at a house situated 
on the bank. The day was warm and but little wind blow- 
ing, and the swarms of black flies were absolutely terrific. 
In vain we frantically waved our moth net among them and 
after making a few desperate charges in the face of the 
thronging pests, we had to retire to the house where the 
windows actually swarmed with them; but here they would 
fly in our faces, crawl under our clothes where they would 
remain and bite in the night. The childrenin the house were 
sickly and worn by their unceasing torments; and theshaggy 
Newfoundland dogs, whose thick coats would seem to be 
proof against their bites, ran from their shelter beneath the 
bench and dashed into the river, their onlyretreat. Incloudy 
weather, unlike the mosquito, the black fly disappears, only 
flying when the sun shines. The bite of the black fly is often 
severe, the creature leaving a large clot of blood to mark the 
scene of its surgical triumphs.” 
