TABANIDiE. 
593 
such resuits are due, not to any poison secreteji by the insect, but to 
dirt accidentally introduced into the wound either by the fly’s proboscis 
or in some other way. 
Unlike most mosquitos, Tabanidce bite only during the day time, 
but they resemble the former in that the females alone are blood-suckers. 
The males live on nectar or the juices of plants and fruits, and the females 
can also subsist on vegetarian diet if they are unable to get blood. Both 
sexes have been observed feeding on the sugary substance exuded by 
Aphids, and it seems probable that some species of Pangonia (females) 
do not include blood in their diet : we have observed them sucking com¬ 
posite flowers at Simla, but never biting. One species of Tabanus at 
Pusa appears to drink water when on the wing, like a swallow, and those 
that we have kept in captivity have drunk freely of sugar and water, and 
of “ Hcematogen ” (a blood-like patent medicine). The sexes are 
generally easily distinguished by the eyes, which touch one another in 
the males and are separate in the females. 
The majority of blood-sucking flies have aquatic or semi-aquatic larvae, 
and the Tabanids, as a family, form no exception to this general rule. 
The eggs (fig. 1 a, PI. LXII) which are 
usually dark-coloured and cigar-shaped, 
or sometimes curved and with a white 
incrustation, are generally laid arranged 
in more or less regular masses on leaves or 
stems of plants overhanging water or the 
mud at the edge of water. When the eggs 
hatch the larvae fall out into the water, 
whence they soon make their way to the 
mud at the bank, where they live until 
full grown, eating living or dead insects, and in captivity preying on one 
another when food is scarce. When full grown they leave the water’s 
edge and make their way further up the bank where they pupate 
just below the surface of the ground. The larvae are apparently 
metapneustic, with well developed mouth-hooks, a retractile head, 
and the body-segments usually furnished with prominent tubercles 
bearing small claw-like spines which assist in locomotion. The tail is 
usually more or less prolonged into a retractile breathing-tube, and a 
round double swelling below marks the anus. A characteristic feature 
iil 38 
Fig. 386— Mouthparts of fe¬ 
male Tabanus , showing ab¬ 
sence of Mandibles. 
(After Nine.) 
