UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 329 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
March 6, 1916 
NOTES ON FIVE NORTH AMERICAN BUFFALO 
GNATS OF THE GENUS SIMULIUM. 
By Arthur W. Jobbins-Pomeeoy, 1 Entomological Assistant. 
CONTENTS. 
Page. 
Introduction 
The adult stage- 
The egg stage 
The larval stage. 
The pupal stage- 
Life cycle and number of generations- 
Insect enemies and parasites 
Simulium as a possible carrier of dis- 
ease 
Bibliography 
Page. 
26 
27 
28 
35 
INTRODUCTION. 
Certain species of the insects known as "buffalo gnats" are im- 
portant enemies of man and domestic animals in the United States 
as well as in other countries. Although the principal area of abund- 
ance in North America is in Canada and the Northern States, out- 
breaks of pests of this group occur as far south as Louisiana and 
Florida. While they are dependent upon running water for develop- 
ment, they make use of very small streams and, to some extent, of 
irrigation ditches, and are consequently found occasionally in con- 
siderable numbers in the drier parts of the country. 
About 20 years ago buffalo gnats attracted great attention along 
the lower Mississippi River. They frequently became so abundant 
that plantation operations were stopped ^on account of very painful 
attacks against live stock as well as human beings. These great 
outbreaks were due to conditions established by the overflow of the 
Mississippi River. The perfection of the levee system has changed 
these conditions so that the outbreaks are less frequent and of greatly 
reduced severity. Nevertheless, these insects are still abundant 
enough to be considered a pest in the Mississippi Valley as well as 
in many other portions of the South. 
The damage done by buffalo gnats results from their painful bites 
and the loss of blood which ensues. When they are abundant they 
1 Resigned Nov. 20, 1914. 
Note. — This paper is of interest to persons living east of the Mississippi River. 
10981°— Bull. 329—16 1 
