Tabanidce, or Horse-flies 
hi 
an active, carnivorous life, feeding mainly on insect larvae, and worms. 
In the forms which have been best studied the larval life is a long 
one, lasting for months or even for more 
than a year. Until recently, little was 
known concerning the life-histories of this 
group, but the studies of Hart (1895), 
and Hine (1903 
+ ) have added 
greatly to the 
knowledge con¬ 
cerning North 
American 
forms. 
Many of the 
species attack 
man with avid¬ 
ity and are able 
to inflict painful 
bites, which 
may smart for 
hours. In some 
instances the 
wound is so 
considerable 
that blood will 
continue to flow 
after the fly has 
left. We have 
seen several 
cases of secondary infection following 
such bites. 
The horse-flies have been definitely 
convicted of transferring the trypanosome 
of surra from diseased to healthy animals 
and there is good evidence that they transfer anthrax. The possi¬ 
bility of their being important agents in the conveyal of human 
diseases should not be overlooked. Indeed, Leiper has recently 
determined that a species of Chrysops transfers the blood parasite 
Filaria diurna. 
80. (6) Larva of Tabanus. 
Photograph by M. V. S. 
80. (a) Eggs of Tabanus. Photo¬ 
graph by J. T. Lloyd. 
