TRANSFORMATIONS OF BUFFALO GNATS. 7 
has observed, are limited to this diet. There are only two definite 
records to the writer's knowledge of Simulium feeding upon any- 
thing other than the blood of mammals. One is by Hagen (1883), 
who states that he found Simulium attacking and feeding upon the 
chrysalids of a butterfly (Pieris) Neophasia menapia Felder. He 
does not, however, state the exact species which he found so doing, 
and remarks that it was similar to the New England "black fly." 
The other record is by H. Pryer, 1 who states that in Japan he found 
Simulium attacking the larva of a sphingid, Smerinthus planus 
Walk., and also the imago of Stauropus persimitis Butl. 
A detailed study was made by the writer in the region of Spartan- 
burg, S. C, of the feeding habits of Simulium venustum, which 
was found from early spring to late fall engorging within the ears of 
horses and mules. Though invariably present on these animals, they 
were seldom found on cattle or on man. The severity of the attacks 
of this species depend both upon the time of year and the time of 
day. It is generally believed that the worst attacks occur in early 
spring and in early fall, and the writer found adults more numerous 
during the first three weeks of September than they had been since 
the middle of June. They appear to be most active from 3 p. m. to 
almost dusk. They are rather easily disturbed while feeding, and 
unless much distended will struggle violently to disengage them- 
selves from the long hairs in the interior of the mules' ears. It has 
been noticed repeatedly that even the well-engorged specimens will 
retract their beaks and successfully fly away and not fall to the 
ground and crawl away to die, as has heretofore been claimed by cer- 
tain writers. The fact that they are so easily disturbed and bite only 
under certain conditions probably accounts for the failure thus far 
of all efforts to get them to engorge while in captivity. While con- 
fined on the human body in a vial they make .frantic efforts to escape 
and after 20 minutes become so exhausted as finally to remain on their 
backs with scarcely a sign of life. Whether the vial was covered to 
exclude the light or not, these experiments were unsuccessful at any 
time of day, both with reared specimens and captured ones. When 
placed in jars containing cloth saturated with defibrinated cow's 
blood a few took a small amount of blood into the crop, but there was 
no distension of the abdomen. 
OVIPOSITION. 
In the method of oviposition the different species of Simulium, 
whose life history has been studied in detail, show characteristic 
adaptations according to their habitat, and may be classified arbi- 
trarily into two distinct groups. Although this grouping applies 
clearly to conditions in South Carolina, it is possible that exceptions 
may be found in other regions. 
1 See Bibliography, p. 35. 
