CHERRY AND PEAR SAWFLY. 55 



blance to little slimy slugs feeding on the upper side of the 

 infested leaves, are often not recognized as caterpillars from 

 this very peculiar appearance from which they take their 

 name. They feed on the leaves of Cherry and Pear, also on 

 Plum, and sometimes on Peach, and on one occasion they 

 have been forwarded to me as feeding on leaves of Quince ; 

 and they do serious mischief by devouring the skin of the 

 upper side of the leaf, so that the remainder appears like a 

 net-work of veins, held together by the skin of the lower side, 

 which is left untouched, and turns to a deep brown colour. 



The Sawflies (see figure, p. 54, with lines giving natural 

 size) are shining black, with the horns rather longer than the 

 thorax (fore body) ; legs black or fuscous, the front ones 

 somewhat lighter at the lower parts ; wings stated to be rather 

 deep fuscous with the apex pale ; nervures and costa (fore 

 edge) black ; stigma brown, and in the second subraarginal 

 areolet a small fuscous cloud. From differences of descrip- 

 tion of colouring of the legs it would appear that this is 

 variable. 



In the case of specimens sent me on the 19th of June, 1893, 

 by Mr. Cresswell Ward, from Neasham Hill, near Darlington, 

 I was uble to watch the early stage of the attack, which is so 

 rarely noticed that I give the observation in detail. 



In this case the active stage of the attack to some of the 

 leaves sent me was only just beginning, the upper surface 

 of the leaf not being as yet stripped of the cuticle in patches, 

 but dotted with little n-regularly circular patches, some less 

 than half a line in diameter. 



The places of egg deposit were very observable. These 

 were noticeable on the upper side of the leaf as little spots, 

 roundish in shape, and whitish in colour (from the upper 

 coat of skin being dead), slightly raised in the middle, and of 

 a somewhat transparent tint just over the contained egg, 

 which was a soft mass, compressible, thick, and somewhat 

 circular in outline. 



Most of the larvae had hatched out, leaving only the white 

 skin cracked where the maggot bad effected its escape, but 

 two eggs still remained unhatched. One of these eggs con- 

 tained the white sawfly larva curled on itself within, and 

 sufficiently developed to be of characteristic shape, that is, 

 with the large segments behind the head, and the hinder 

 portion of the maggot with the segments much narrower. 

 In the other egg the contents were not j^et sufficiently deve- 

 loped to be defined in shape. I did not see any larva in the 

 act of coming out of the egg, but the smallest of them were 

 as a general thing of a yellowish colour. 



The little white blisters, or patches, of white dead skin 



