22 
the data from the collections of the State Laboratory of Natural 
History and the Entomologist’s Office, and all the information 
contained in the field notes of my office, running back over many 
years, with a view to presenting at this time as full a report upon 
this topic as is practicable; and this paper is submitted as a pre¬ 
liminary statement. 
Altho it was originally prepared with special reference to the 
medical bearings of the subject, account has here been taken of 
the fact that the black-flies, the different species of which are 
known by various common names, are well-known pests of the 
domesticated animals, especially in the southern part of this state, 
in spring and in the vicinity of the great rivers; and of the fur¬ 
ther fact that these insects are a decided annoyance and an occa¬ 
sional cause of serious injury to human beings exposed to their 
attack. They are worst, as a rule (especially to the southward), 
after periods of high water and a consequent overflow of the 
bottom-lands of the larger streams. We are likely, consequently, 
to have unusual trouble along the Wabash, Ohio, and Mississippi 
rivers this year if the extraordinary high water of the early spring 
continues thru the breeding season of the buffalo-gnats. 
General Description 
The buffalo-gnats, or black-flies, all species of the genus Simu- 
lium, are small two-winged insects with thick, hump-backed bodies 
and sharp piercing and sucking beaks. They vary in length, ac¬ 
cording to species, from 1/25 to 1/6 of an inch—1 to 4 1/2 mm. 
They are notorious for the immense numbers in which they swarm 
in early spring, especially along the larger streams, and for the 
painfulness of the punctures made by the females (the males be¬ 
ing inoffensive) and the ferocity and persistence of their attack 
They are, generally speaking, more annoying than seriously injuri¬ 
ous to mankind, altho several deaths have been more or less plausi¬ 
bly attributed to their attack; but to domestic animals—especialh 
to cattle, horses, and mules, and even to poultry—they are a terri¬ 
ble and terrifying scourge. 
As is very commonly the case with blood-sucking Dipt era, the 
young, or larv?e, of these flies are aquatic. The eggs are laid in 
patches upon objects under water, the larv?e transform there to 
pupse, and the pup?e to winged adults, which escape to the surface 
each in a bubble of air absorbed from the water thru the gills of 
the pupa, and stored up under its cuticle. The larv?e are so abun¬ 
dant locally, under the most favorable conditions, that the w?ter 
is said sometimes fairly to boil as the winged insects burst from 
its surface, each in its air bubble. 
