102 PEAR. [1899 



been proved by careful examination of specimens. This identification 

 is of some importance, for the most serviceable account, both practi- 

 cally and scientifically considered, which has been recently publislied 

 is, I believe, that of Mr. C. L. Marlatt, First Assistant Entomologist 

 to the U.S.A. Department of Agriculture.* 



All who have studied the subject will be aware of the difficulties 

 arising from multiplicity of scientific names of the insect, and Mr. 

 Marlatt, in his paper referred to below, mentions that in Europe this 

 insect has received at least 7iine different specific names, and has been 

 referred to some eieiht (jenera. In the two appellations given at my 

 own heading, I have followed the guidance of our European writer. 

 Prof. Westwood, and also given the more recent appellation especially 

 selected by Mr. P. Cameron f ; in Mr. IMarlatt's paper he gives the 

 attack as that of Kriocenupoidea limacina of Retzius, one of the earliest 

 observers (in 1783) of the infestation, which I have therefore added. 



The stage of attack at which the presence of the mischief is usually 

 first noticed with us is during the early part of the summer — as, for 

 instance, about the middle of June — when the little Slug-like grubs 

 may be found feeding, though usually not more in number than three 

 or four, on the upper skin (epidermis) of the leaf. This they sometimes 

 clear wholly away, leaving only the network of veins beneath it, and 

 the skin of the lower side of the leaf, which consequently turns brown 

 and dies ; and in cases of bad attack, the condition of the growing 

 fruit and the health of the tree are necessarily injured by the loss of 

 leafage. Often, however, the upper surface is only eaten off in 

 patches, but still enough damage caused to draw attention to the 

 presence of the leaf enemy. 



Tiie larvae, or Slugworms, are for most of their lives of the shape 

 figured at a, p. 101, about three-eighths of an inch in length when 

 full grown, somewhat broader and thicker at the fore part of the body, 

 and covered with a blackish or greenish slimy exudation, giving the 

 Slug-like appearance from which the larva takes its popular name. 



After feeding for five or six weeks they moult off their slimy coats, 

 and appear as ordinarily shaped caterpillars, buffer yellowish in colour, 

 dry (that is, no longer covered with a coat of slime), and transversely 

 wrinkled. In this condition the tiventy-tivo pairs of feet (that is, three 

 pairs of claw-feet, and a pair of sucker-feet on each of the other 

 segments excepting the fourth) are much more easily distinguishable 

 than when they are in Slugworm state, though the pair at the end of 



* See "The Pear Slug, Eriocampoides riwacina, Eetzius" : Circular No. 26, 

 Second Series, United States Department of Agriculture, Division of Entomology, 

 p. 7. Washington, 1897. 



t ' British Phytophagous Hymenoptera,' by P. Cameron, vol. i. p. 224. Eay 

 Society. 



