COLEOPTERA. — CHRYSOMELID^. 389 



The transformations of these insects have been figured by various 

 authors. By Lyonnet (Post/i. 3Je?u. pi. 12. C. Populi and dorsalis) ; 

 Albin (Natural Hist. Engl. Ins., Lond. 1720, 4to. pi. 63.) ; Frisch 

 (vol. i. pi. 7. t. 8.) ; Goedart (No. 118.) ; De Geer (3Iemoires, vol. v. 

 pi. 8. fig. 16 — 22.) ; and by SchiifFer, who has given a very elegant and 

 complete series of figures of the natural history of C. Populi (Ahhandl. 

 der Insect, vol. iii. art. 4.). In the summer of 1837, I observed this 

 species in immense profusion, in all its states, on the small sallow bushes 

 in the Pare de Belle Vue, near Paris ; the young shoots being com- 

 pletely destroyed in many instances. Dr. Ratzeburg has also pub- 

 lished a very complete series of figures of the various states of the 

 closely allied species Chrysomela (Lina) tremulee, together with details 

 of the structure of the mouth of the larva and imago. (Die Forst- 

 Ins. Col. pi. XX. f. 3.) De Geer hc\s also figured the transformations 

 of Chrysomela aenea and of C. Betulse {Mem. vol. v. pi. 9.), the larvae 

 of which are very similar to those of C. Populi ; the pupa of the for- 

 mer, however, differs in having the abdominal segments more con- 

 stricted. The same author has also figured the transformations of C. 

 haemoptera, the larva of which is thick, fleshy, and without the tu- 

 bercles, which are so conspicuous in the preceding, and others more 

 resembling the larva of Timarcha. The larva, according to De Geer, 

 feeds upon the Hypericum perforatum. Dr. Heer has also described 

 and figured the various states of a new species (C. Esclieri //.), giving 

 a minute analysis of the oral organs. Sec, and of the mucus-secreting 

 tubercles of the back. (Observ. Eniomol. 1836, p). 6.) 



The larvae of some species of this family feed, in society, upon leaves, 

 preserving one or more most orderly rows. This is the case with a 

 species figured by Rosel (Insect. Belustig. vol. ii.. Scarab, terrestr., 

 cl. 3. t. 1.), in which the larviu are arranged in three rows, six or 

 seven abreast ; and which, from the figure of the imago, appears to be 

 that of Chrysomela armoraciac, or an allied species. I have also traced 

 the transformations of the C. Vitcllina> (fig.\'f>. 18. a), the larvje 

 (fig- I'S. 18. h) of which feed upon the willow, in the same manner, 

 but only in a single row, eating only the surface of the leaf ( 48. 18. 

 c?), and leaving their exuvia; attached to its surface (fig. 48. 18. r). 

 They were found at the beginning of September, shortly after which 

 they descended into the earth, and assurned the pupa state (fig. 48. 19, 

 20.), and appeared in the perfect state at the beginning of October. 

 The larva of this insect is very similar to that of C. Populi, except 



c c 3 



