LIFE-ITISTORT OF A MONOPirLKBUS. 155 



Pakt III. — On ihe Life- History of Vedalia Gueriuli, Crotch, 

 predaceous upon M. Stebbingi, Green. 



Vkdalia Guekinii, Crotch, Rev. Coccinell. p. 282 (Loud. 

 •1874). (PI. 17. figs. 2-9.) 



The following are my descriptions of the larva and pupa, made 

 from living specimens : — 



Larva. — When young the larva is black in colour, with three 

 pairs of stout thoracic legs. During its first two moults it 

 appears to retain this colour, being long and narrow with a well- 

 developed head and mouth-parts. As it grows in size it becomes 

 more oval, and the colour changes to white and black or reddish 

 with white markings or a greyish purple. The grub is often 

 covered with a certain amount of the. white powdery material 

 which covers tlie older stages of the Monophlehus upon which it 

 feeds. The young larva has a number of tubercles upon its 

 dorsal surface. When full-grown the larva is 12*5 mm. long, 

 and has a well-developed head, which is narrower thiin the ten 

 segments of the body which follow it. Of these latter, the 

 middle ones are the broadest, the grub tapering to each end. 

 On each of these ten segments there are four dorsal tubercles, 

 two on each side, thus giving four rows of dorsal tubercles. 

 These segments are also fringed on either side by projecting 

 teeth-like processes resembling a saw-edge, giving the insect a 

 serrate appearance at the sides. The last two f-egments make 

 up the dark reddish-black pad-like apparatus which terminates 

 the body, the end of which forms a kind of sucker which is very 

 adhesive and enables the larva to cling to the smoothest bark by 

 its means. The sucker is used in feeding, and also in fixing' 

 itself permanently to a twig or leaf before charging to the 

 pupal state (PL 17. fig. 4 a). The arrangement of the segments 

 makes the body extremely pliable, and the grub can roll itself 

 up almost into a ball. The ventral surface is coloured like the 

 dorsal aspect, but has no tubercles. Just before pupating the 

 Jarva often changes from the white and. black or greyish-purple 

 colour to a brick-red. 



Pupa. — When about to pupate, the larva attaches itself either 

 to the upper or under surface of a leaf or to a tvtig- or rough 

 b;irk by means ot the posterior adhesive pad, its body projecting 

 at an angle from the point of attachment, and assuming a curved 



