EO 
DIPTERA. 135 
théy attack sores, scratches, ulcers, etc., and by passing from one per- 
son to another, or from dogs, cats, or other animals with sores to 
healthy individuals, become a most dangerous source of disease 
contagion. 
So far as described the plague is greatest in the Southern States, 
especially Florida, Alabama, and Texas, and as similar species are 
common to many parts of the country, there 1s little doubt that when 
investigated many of the annoying gnats will be found to come within 
this group. Indeed, I feel confident that in years past insects of this 
character have been often encountered in the Mississippi Valley, as the 
hard bodies and persistent efforts to enter eyes have been noted, when 
no attempt was made to collect specimens or place them entomologically. 
The flies are strictly diurnal, and continue to be troublesome from early morning 
till near sunset, being most aggressive during the bot and sultry hours of the after- 
noon. They preferably frequent open and sunny places, while in the shade of dense 
Fic. 72.— Hippelates plebejus—much -nmarged (from Schwarz). 
forests their presence is not noticeable. They are equally troublesome in the coun- 
try away from human habitations, and in the streets of small towns, but I do not 
recollect having seen them in any number on the streets of the larger cities. They 
enter the houses, but evidently do not feel at ease in the 100ms, for they do not attack 
people, but congregate on the panes of windows, if these happen to be closed. 
The life histories are unknown, but Mr. Schwarz suggests the stems 
of reedy plants or the piles of decaying reeds along shores of lakes or 
marshes as possible breeding grounds. 
With regard to remedial measures Mr. Schwarz says: 
Until some light is thrown on the life history of the tlies 1t is impossible to sug- 
gest any remedial measures to be adopted for the general abatement of this pest in 
agiven region. Very little can be said regarding protective measures. To kill the 
flies, as we instinctively do the mosquitoes, by a slap of the hand, is of no avail 
against the Hippelates, because they are too numerous and for other obvious reasons, 
