4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I25 



It is the purpose of the present study to give as complete an account 

 as possible of the Simuliidae of Guatemala, so that their role in the 

 transmission of onchocerciasis can more easily be appreciated. It has 

 been felt advisable to give first a general discussion of the importance 

 of this group of flies, and to present epidemiological factors in Guate- 

 mala that may be involved in the transmission of the disease. Then 

 follows the body of the paper, which includes the taxonomy, ecology, 

 and distribution of all species of black flies that have been collected 

 in Guatemala, with special reference to the principal anthropophilic 

 species. The biting habits, resting places, flight range, longevity, and 

 attempts to colonize those species that most commonly attack human 

 beings are discussed in detail. It is hoped that this information will 

 serve as a firm foundation upon which can be developed an efficient 

 program of control of the vectors of onchocerciasis. 



IMPORTANCE OF THE SIMULIIDAE 



The flies belonging to the family Simuliidae affect man and animals 

 both by their bites and as intermediate hosts of parasites. For years 

 they have been recognized as serious pests of domestic and wild ani- 

 mals. In the literature can be found numerous references to heavy 

 animal losses sustained along the river basins of northern and south- 

 eastern Germany, along the Danube, in the forested sections of Siberia, 

 in Australia, Canada, the United States, and in parts of South America 

 due to the attack of these flies. Animals listed as having been affected 

 include mules, horses, cattle, hogs, sheep, dogs, cats, deer, foxes, 

 rabbits, turkeys, chickens, ducks, and other fowl. 



PESTS 



Ciurea and Dinuflescu (1924) describe the destructive outbreaks 

 of the goloubatz fly (Simulium colombaschensis (Fabricius) ) in parts 

 of Rumania in 1923. Tremendous numbers of wild and domestic ani- 

 mals were affected, and more than 16,000 domestic animals were re- 

 ported killed. The flies also attacked man, biting voraciously, but did 

 not cause human deaths. In the Western Hemisphere, Riley (1887) 

 gives a lucid account of the outbreaks of Cnephia pcctiarum (Riley), 

 the buffalo or turkey gnat, in the lower Mississippi Valley of the 

 United States, with the loss of large numbers of mules, horses, 

 turkeys, hens, and hogs. Numerous cattle, sheep, dogs, and cats also 

 suffered severely. Rempel and Arnason ( 1947) describe the heavy out- 

 breaks of Simulium arcticum Malloch in central Saskatchewan, 

 Canada, during the years 1944, 1945, and 1946. The flies were wind- 



