Abnormal Feeders 311 



Lepidoptera, the perfect insects sucking honey and 

 the caterpillars eating leaves or other parts of plants. 

 The great Death's-head Moth (Acherontia), however, 

 instead of gathering honey for itself from flowers, is 

 known often to enter hives and rob bees, while the 

 presence of small caterpillars feeding on the comb has 

 already been mentioned. Butterflies sometimes forsake 

 honey for such unsavoury food as blood from the 

 wound of a mammal, or the juices of a putrefying 

 carcase. Several instances are known of caterpillars 

 which eat other insects. The larva of Cosmia trape-zina 

 feeds on oak and other leaves, but devours caterpillars 

 smaller than itself which happen to get in its way ; 

 while other species are said to prefer insects to leaves 

 whenever the opportunity arises; a small "looper" 

 caterpillar has been observed to eat a larva three 

 times as big as itself (l8l). A specially interesting 

 carnivorous caterpillar is that of Erastria scitula, a 

 south European Noctuid moth (fig. 1 68), whose 

 female lays her eggs singly and far apart on trees 

 infested with scale-insects. When hatched the young 

 caterpillar selects a large female coccid, eats its way 

 through the scale and devours the insect beneath. 

 As it grows it makes a case for itself of the scales of 

 its victims and its own excrement, bound together by 

 silk which it spins. Protected by this covering, which 

 closely resembles the bark of the tree, it roams about 

 eating in its later stages several coccids every day 

 (178 b). 



Protection by foreign Objects. — The case-form- 

 ing habit of the Erastria caterpillar introduces a fresh 

 subject in the life of insects — the various ways in 

 which protection from enemies, or shelter is secured. 

 This caterpillar carries about its hard case wherever 

 it goes. In correspondence with this habit its body 

 is short and stumpy (fig. 168 a, h) ; three pairs of pro- 



