ALEURODIDiE. 
749 
The antennae are usually seven-jointed and moderately long ; the 
compound eyes are distinct and there are usually two ocelli. The wings 
are of nearly equal size, with bristles 
or ornamentation at the margin, the 
thorax well developed. The abdomen 
is ovate and thickset, the vasiform 
orifice present (see below) the male 
with a short penis. Legs are of moder¬ 
ate length, the insects being able to 
walk and fly. 
Peal worked out the life-history of 
some species and more has since been 
learnt of this group. The eggs are 
usually attached to the leaf by a very 
short stalk and are smooth, shiny, oval 
in form. They are laid in clusters on 
the leaf, often in a circular band formed 
by the female revolving as on a pivot 
Fig. 524 -Aleurodes Barodensis while depositing them. The young 
Egg, Nymph, Pvtje. (I. M. N.) } arva that issues is active, of the flat¬ 
tened oval shape of a Coccid larva, 
with legs and antennae; it is active 
for a short time and moves about till 
it finds a satisfactory place when it 
settles down and fixes itself. It 
then moults and becomes a legless 
scale-like insect, flattened and press¬ 
ed to the leaf ; there is usually a 
development of wax as a covering, 
the wax being the product of dermal 
glands, as in the Coccidce / this wax 
often takes very bizarre forms. The 
characteristic of this and the later 
immature stages is the “ vasiform 
orifice, ” an opening on the dorsal 
surface of the abdomen leading 
into a space in which lies a narrow 
Fig. 525 —Aleurodes Barodensis. B. 
Larva. C. Pores of larva. D. Margin 
of larva. E. Vasiform orifice and 
operculum. (I. M. N.) 
