268 
HALF HOURS WITH INSECTS. [Packard. 
selves. This paradox may be explained by a glance at a 
Selandria larva (Fig. 207) which sometimes occurs on the 
chestnut. Its body is entirely concealed by a cottony secre¬ 
tion which rises half an inch above the body. A group of 
these sluggish caterpillars could feed exposed on a leaf with 
impunity. The bark lice, such as Eriosoma, cover them¬ 
selves with a cottony exudation which serves as a disguise. 
Many bright colored flower beetles are protected by their 
resemblance to the tints of the flowers in which they hide. 
The Galeruca and Clytus, almost invariably found on the 
golden rod in September, are thus protected. 
Why butterflies are so much more commonly seen than 
their caterpillars is not known. It is probably due to the 
fact that the latter are often of 
the color of the leaves on which 
they feed. The caterpillar of the 
Colias Philodice , our common sul¬ 
phur yellow butterfly, which lives 
on clover, is rarely found, owing 
to its pea-green tint so much like 
that of the clover leaf on which it 
feeds. It is possible that the caterpillar is so well protected 
that the butterflies can afford to have their numbers thinned 
out by predaceous insects and birds. So with the caterpil¬ 
lars of the white cabbage butterflies, whose dark green vel¬ 
vety coats so thoroughly assimilate them with cabbage or 
turnip leaves or stalks. The caterpillar of Vanessa Antiopa 
is one of the most conspicuous objects in nature, large clus¬ 
ters of these black spiny creatures feeding exposed on the 
leaves of the willow and other plants. It is probable, how¬ 
ever, that bristling as they are with spines, birds do not 
fancy them; but the butterflies as well as the chrysalides 
assume the tints of dead leaves and old wood, and the but¬ 
terfly may be easily confounded with the trunks of the trees 
on which it rests, as it does not settle on the ground as in 
12 
Fig. 207. 
Selandria Larva. 
