598 
DIPTERA. 
other insects. The hosts are mostly Hymenoptera, bub other groups, 
including Acridiidce (Locusts), are known to be attacked, and a 
species of Geron (G. argentifrons , Bru.) has been found at Pusa 
parasitic on a Tortricid moth, Laspeyresia jaculatrix. It is not 
uncommon to see female Anthracines hovering up and down over 
the surface of brick walls and other places where nests of Hymenoptera 
are likely to be, evidently exploring to find a suitable place for their 
eggs : these they seem to jerk from the abdomen while still on the 
wing, as described by Fabre, but no Indian species have yet had their 
life-histories properly traced. They carefully inspect likely-looking 
holes and cracks in bricks or wood, and we have more than once 
beguiled the common Argyramceba distigma into wasting much time 
over an attractive “ hole ” painted on a piece of paper pinned up on 
the wall or the verandah of the bungalow. From the biological point 
of view the chief interest of these life-histories centres in the very 
remarkable changes of form undergone by the larvae, each change being 
specially adapted to help it in the progressive stages of its career. 
Fabre has studied these changes in the case of an Argyramceba and 
the following account of his work is abridged from Dr. Sharp’s volume 
on Insects (Pt. II) in the Cambridge Natural History. The victim in 
this case is the Mason-bee ( Chalicodoma ), one of those Hymenoptera 
which build hard nests of mud, like those commonly seen about the 
corners of bungalow walls and such like places. The parent fly 
hovers over one of these 
nests and drops upon it a 
minute egg whence emerges 
a tiny slender larva hard¬ 
ly Ao inch long. After re¬ 
maining quiet (all the time 
in a fasting condition) for 
about a fortnight, the little 
animal begins with extra¬ 
ordinary energy and per¬ 
severance to explore the 
surface of the nest until it 
finds some tiny crack large 
enough to give it access to 
Fig. 390 —Larva of Hyperalonia in resting 
STAGE, LYING NEAR THE DESTROYED SCELI- 
PHRON LARVA SHOWN ABOVE IT X 2. 
