754 
RHYNCHOTA. 
brightly coloured, the colouring matter in the tissues showing through 
the skin. In such small insects, colour schemes appear to be of little 
importance though a few are cryptically coloured. In all, the females 
and males are sharply differentiated, the former inactive and wingless ; 
the latter small, active and winged. In their first two stages they are 
indistinguishable, the structure being similar throughout the group (see 
Plate LXXXIII). The young are oval, flattened, with legs, antennae and 
eyes ; the form changes at the first moult, the body becoming flattened 
and adapted to the parasitic life on the plant. Antennae, eyes and legs 
are no longer to be found in many inactive species, the mealy bugs and 
some active species retaining them. The female normally passes through 
three moults with small changes; the male after the second moult either 
gradually or immediately becomes a pupa ; wing pads are slowly formed 
and the resting stage is entered on some days after the second moult. It 
is thus not a true pupa, but rather a resting nymph. The degree of 
degeneration varies with the species and the adult pregnant female is 
commonly a sac, firmly fixed to the plant by means of the suctorial ap¬ 
paratus. The anal opening is on the dorsal surface, the genital opening on 
the ventral. The spiracles are reduced to two pairs, on the lower surface, 
at the termination of air spaces that lead to the edge of the body ; in 
some there are special spiracular processes which bear the spiracle at the 
outside of the covering. The mouthparts consist of the short beak-like 
rostrum from which fine suctorial threads arise. In the winged male the 
antennae are long and many jointed; the eyes large; the body elongated 
and formed as in flying insects. The wings are narrow, with few veins; 
the second pair of wings is reduced to a hooked process which 
engages with the edge of the wing. At the end of the abdomen are 
frequently long many jointed cerci, one pair in some species, several 
pairs in a few (Monojohlehus) ; the penis is often conspicuous and ex- 
serted. The mouthparts are absent and in their place is a pair of eyes. 
In many species of Coccidce reproduction is apparently similar to 
that of other insects. In a large number, however, we find that parthe¬ 
nogenesis is apparently general, the colonies consisting of females only, 
males not being commonly found and possibly occurring only at 
intervals. Very little is known accurately of such cases ; the females 
produce enormous numbers of eggs and these eggs all hatch to females, 
which in turn produce female eggs parthenogenetically. 
