570 Mr. C, L. Withycombe's Notes on 



uncommon. Frequently C. perla is to be met with in 

 pine woods. The first brood appears about the middle 

 of May, and by the end of June has generally died out, 

 stragglers may be found, however. The second brood, 

 which is alvi^ays small, occurs from the end of July through- 

 out August. The majority of the insects do not emerge 

 as a second brood, but pass the winter as larvae within 

 the cocoon. 



Eggs are laid on the undersides of leaves, being mainly 

 found on hawthorn, hazel and field maple. They are 

 laid singly, or in well-spaced clusters of not more than six, 

 under natural conditions, but larger clusters have been 

 obtained in captivity. The egg is '9 mm. long, colour pale 

 green when first laid. The stalk averages 6 mm. in length. 

 In a day or so, patches of yellow appear through the egg- 

 shell, especially at the micropylar end, and in three or 

 four days the general colour is greyish. Finally, brown 

 lines indicating the segmentation of the embryo within 

 appear, and about eight or nine days after oviposition 

 hatching takes place. 



The newly-hatched larva is nearly 2 mm. long, body 

 colour pale greyish-brown. The head is dark brown or 

 blackish, dorsally the black colour may be divided into 

 three main areas. In the second instar the head may 

 exhibit the characteristic markings, but this is not always 

 the case, and one must often wait until the third instar 

 before a larva can be definitely distinguished from that 

 of C. septemjnmctata. The colour of abdomen and thorax 

 is now brownish-white with vaguely defined darker brown 

 latero-dorsal bands, leaving the sides and central dorsal 

 area lighter in colour. The metathoracic lateral promin- 

 ences are always darker than those of any of the other 

 segments. Sometimes larvae in their second instar are 

 almost exactly as in the third, and can then, of course, 

 be identified at once. 



Descriftion of Third-instar Larva. (Plate XLII, fig. 3.) 



Length about 8 mm. when full fed. Body covered with con- 

 spicuous warts bearing tufts of setae. General colour dark brown 

 on a creamy-yellow or greenish-white ground. 



Head whitish, markings black. A central, elongate-oval spot 

 extending from the middle almost to front margin of head. Two 



