998 Marvels of the Universe 
The Maggot taking its rest between meals. 
(Three times natural size.) 
Photos by] (H. Main. . 
THE CATERPILLAR-HUNTING MAGGOT,. 
The Maggot hunting between the leaves of 
Asphodel, which show the ravages of the cater- 
pillar. Some of the silk-threads spun to draw the 
leaves together are noticeable. (Three times the 
natural size.) 
A CATERPILLAR-HUNTING MAGGOT 
BY HUGH MAIN, B.SC., F.E.S. 
THE life-history of a Hover-fly was told and illustrated in 
a preceding article. There we saw how the grubs hunted 
around and devoured large numbers of the aphis, or 
green-fly, that infests sweet-peas and other plants. 
Although the food of the larve of many different 
species of Hover-flies consists of green-fly, this is not an 
invariable rule in this group of insects. 
There is found in various parts of the South of Eng- 
land, but by no means commonly, a rather large and 
handsome Hover-fly. It has no common English name, 
so we must give its scientific name, Xanthandrus comtus, 
which may be translated as “ The fly whose male is 
adorned with yellow markings.’’ As in so many of the 
lower animals, the female is less ornamented than her 
mate. 
Nothing seems to have been observed in this country 
of the life-history of this particular Hover-fly. In the 
South of France, however, where it 1s more commonly 
met with, it may be found and followed through its 
various stages. 
In April the asphodel is throwing up its bright green 
leaves and beautiful spikes of flowers. It is abundant in 
the neighbourhood of Hyéres. Like other plants, it has a 
host of insect life to support, larve of moths, beetles, and 
other small fry, finding in it a temporary home and a 
ready supply of succulent food. 
It can be noticed by anyone whose eye is not entirely 
attracted by the flowers that many of the triangular green 
leaves are spun together by threads of silk. On gently 
pulling these apart a greenish, wriggling caterpillar may 
be discovered, which lives as in a tube, with its food all 
round it, and protected, one would imagine, from the 
observation of any enemies that would like to make a 
meal of it. If we wish to find this caterpillar, to rear 
from it the beautiful little moth, Hastula hyerana, we 
have to hunt for it where we notice the spun-together 
leaves. Perhaps, however, we shall find that we are not 
the only hunters, and that a long, greenish, semi- 
transparent maggot, with the blackish central area of 
its back surrounded by lighter parts, is crawling about 
and pushing its narrow head in between the drawn- 
together leaves, evidently also on the hunt for some- 
thing. A careful watch may reveal one of these hunters in 
the act of finding its prey—namely, the caterpillar of which 
we also are in search. When we find one of these cater- 
pillars it commences to wriggle away immediately ; but 
