182 STATES OF INSECTS. (Larva.) 
cled at the base with a hairy tuft*. Others, as those of 
Melitea Artemis, Cynthia, &c. have each segment beset 
on the back with from seven to nine fleshy, pubescent, 
wedge-shaped protuberances ; two larger ones projecting 
over the head. Under this head, too, may be noticed, 
the glutinous secretion which clothes the grub of Cionus 
- Scrophularia, a little weevil; and of Dolerus ? Cerasi, a 
saw-fly, and that waxy or powdery substance which 
transpires through the skin of the larvae of several Aphi- 
des, Chermes, Cocci, Allantus ovatus, &c. The plant- 
louse, whose extensive ravages of cur apple-trees (My- 
zoxyla lanigera) were before described to you», is 
covered and quite concealed by this kind of substance, 
so that the crevices in the bark which they inhabit look 
as if they were filled, not with animals, but with cotton. 
The insect, also, that forms those curious galls produced 
upon the spruce-fir, and which imitate its cones (Chermes 
Abietis L., Aphis De Geer) secretes a similar substance. 
In these and other cases of the same kind, this matter 
seems to be, if I may so speak, wire-drawn through 
numerous pores in certain oval plates in the skin, more 
depressed than the rest of the back, arranged regularly 
upon the segments, and exhibiting minute tuberosities. 
When young, these animals have more of this secretion 
than when more advanced: it then hangs from their 
anal extremity in locks«. 
But the insects most remarkable for a coveriug of this 
nature are those Coccid@e of which Bosc has made a ge- 
nus under the name of Dorthesia. De Geer is the first - 
“ Ros. ¢. 211. > See above, Vo. I. p. 29, 200—. 
° De Geer iii. 111. Comp. 12]. It would be as well to adopt the 
French word flocon, instead of locks or flocks, which strictly mean 
very different things. 
