42 
IMPORTANT AND FAMILIAR INSECTS 
turn into pupae. When they are ready to pupate, they eat 
their way out of the body of the caterpillar and spin a cocoon 
which in some cases re- 
Figure 29—Tent Caterpillars. 
They are seen resting during the hotter 
part of the day on the trunk of the apple 
tree. Later in the day they go out and 
eat the foliage. Note the great blankets 
of silk that they have spun on the side of 
the tree. Fortunately most of these cater¬ 
pillars were attacked by ichneumon-flies, 
tachina-flies, and chalcis-flies so that very 
few matured. The year following these 
destructive insect pests did very little 
damage owing to the successful campaign 
of their numerous insect enemies. 
mains attached to the 
body of the caterpillar 
(Figure 25). These par¬ 
asitic larvae so weaken 
the caterpillar that it 
dies. We shall learn 
more of these Ichneu- 
mones later. 
Next to Ichneumones, 
the birds are probably 
the most active enemies 
of the Lepidoptera. 
Many birds live entirely 
upon caterpillars and we 
find birds that seek them 
as food in all stages of 
their development and 
growth. The eggs laid 
on the twigs and trunks 
of trees are eaten by 
chickadees, nuthatches, 
brown creepers, and 
woodpeckers. The larvae 
are eaten by many birds, 
notably by cuckoos, blue¬ 
birds, wrens, blackbirds, 
orioles, blue jays, crows, 
and house sparrows. The 
cocoons and pupae are 
sought by the chickadees, 
woodpeckers, nuthatches, and brown creepers. The adult 
insects are preyed upon by house sparrows, chipping sparrows, 
