314 ENTOMOLOGY 
propagate insect enemies of various introduced insect pests, 
and some of their efforts have been crowned with success, as 
was notably the case when Novius cardinalis, a lady-bird 
beetle, was taken from Australia to California to destroy the 
fluted scale. 
Form of Parasitic Larve.—The peculiar environment of 
parasitic larve is responsible for profound changes in their 
organization. ‘These larvee, in general, are apodous, the body 
is compact and the head is more or less reduced, sometimes to 
the merest rudiment. These characters, occurring also in such 
dipterous larve as live in a mass of decaying organic matter 
and again in those hymenopterous larvee whose food is pro- 
vided by the mother or by nurses, are to be attributed to the 
presence of a plentiful supply of food, obtainable with little or 
no exertion, and indicate, not primitive simplicity of organiza- 
tion, but a high degree of specialization, as we have said before. 
The embryonic development of parasitic larvze is frequently 
highly anomalous, as appears in the chapter on development. 
Maternal Provision.—Ixcepting several families of Hy- 
menoptera and the Termitidz, few insects make any special 
provision for the welfare of the young bevond laying the eggs 
in some appropriate situation. Many insects, as walking- 
sticks (Phasmidz) and May beetles (Lachnosterna) simply 
drop their eggs to the ground, leaving the young to shift for 
themselves. Most insects, however, instinctively lay their 
eges in situations where the larva is sure to find its proper food 
near at hand. Thus various flies and beetles deposit their eggs 
on decaying animal matter, butterflies and moths are more or 
less restricted to particular species of plants, and parasitic 
Hymenoptera to certain species of insects. The beetles of the 
genus Necrophorus go so far as to bury the body of a bird, 
mouse or other animal in which the eggs are to be laid; and 
in this instance the male assists the female in undermining and 
afterward covering the body. A similar co-operation of the 
two sexes occurs in the scarabzeid beetles known as * tumble- 
bugs,” a pair of which may often be seen rolling along labori- 
