ON INDIAN PARASITIC FLIES. 
965 
<;overs her head and thorax. The proboscis of the female is modified 
to enable her to cut into the skin of the host but the homology with the 
normal Streblid proboscis can be discerned. The following summary 
is based on the observations made by Mr. F. Muir, an American ento- 
mologist.* The adult flies emerge from the pupa-case which lies upon 
the groimd in caves and other haimts of bats. Both sexes are per- 
fectly normal flies with fully developed legs and wings. They are of 
a light reddish-brown colour with a pair of large rounded wings. 
Both sexes are destitute of eyes and only the male has maxillary 
palps or feelers. The most striking features in the female is the enor- 
mous size of the proboscis and the fact that head and thorax appear 
as though welded into one piece. But for this she has the normal 
appearance of a small fly and nothing suggests how she will end her 
days. The proboscis is a chitinous, broad, flattened, blunt cone 
with a base somewhat wider than the head. At the apex of the pro- 
boscis there arise fourteen rows of chitinous blades. They are like 
circiflar saws cut in half so as to form a row of semi-circles placed 
side by side. 
There is a short ga]3 in our knowledge of the life liistory but the pair- 
ing of the sexes probably takes place in a normal manner whilst the 
female is winged. The female then seeks her host and by theaid of 
the blades at the end of her proboscis cuts through the skin of the bat. 
The parasites were always foimd imbedded in the same position under 
the skin at the base of the ear. There were usually two, rarely three, 
but sometimes only one specimen on a bat. When she is imbedded 
the abdomen enlarges and engulfs the head and thorax so that even- 
tually they lie at the bottom of a pit at the anterior end of the abdo- 
men. The fly burrows into the bat head foremost and the posterior 
end of the abdomen remains protruding. The presence of the para- 
site makes itself visible as a swelling with a small pearly- white body 
protruding at one side thereof. When cut out of the host the para- 
site appears as a semitranslucent white flask-shaped body four to 
five millimetres long. No head or thorax is visible. Wings and legs 
are gone. How and when the female gets rid of them remains a 
mystery. The stumps can be detected but there are no traces of 
legs or wings in the cavity formed under the skin of the bat. The 
proboscis is so rigidly fixed to the head that it could not be used to 
sever wings or legs. They must, by some other means, be got rid 
of before the female insect is completely imbedded. In this dismal 
fashion she produces her larvae which are born mature, fall to the 
ground and pupate at once. The male fly is not provided with ade- 
quate weapons on his proboscis to cut through the skin of a bat. He 
* Muir found that at Amboina only one species of bat (Miniojiterua schreibersij 
was attacked by Ascodipteron speiserianum and that 28 percent of the bats examined 
were infested. P. Muir: Two new species of Ascodipteron. (1912) Bull. Mus. Zool. 
Harvard, Vol. LIV. pp. 351-366. 3 Plates. 
