1899] PEAR AND CHERRY SAWFLY. 107 



" I felt it was useless applying insecticides to the few remaining 

 larvae, and that my only course was to denionstrate to my applicant 

 the absolute necessity for clearing away the surface soil. I had on 

 no previous occasion dug out the cocoons of this pest, and therefore 

 was not at all certain of the most favourable spot to search for them ; 

 but a former experience with the cocoons of the Gooseberry Sawfly 

 (NematJis ribesii) enabled me to form an idea as to its nature and the 

 difficulties of finding so comparatively small an object, which exactly 

 resembled a crumb of earth. 



" My attention was directed to an examination of the soil between 

 the roots at the base of the tree ; this was carefully rubbed between 

 the palms of the hands as being the surest way of finding the loose 

 cocoons in the earth, but none were found in it. 



"Noticing patches of apparently loose earth still attached to the 

 bark of the roots, these were carefully removed, and beneath them were 

 found several cocoons attached to the hark. Numbers of others were 

 clustered together at the bifurcations of the roots ; and further away 

 others were more isolated. Nothing could be more interesting than 

 the wonderful way the cocoons resembled the colour and irregularities 

 of the bark, and when fixed in a crevice it was impossible to detect 

 them without probing and rupturing the cocoon. Portions of the bark 

 bearing the cocoons were removed and photographed (fig. 1, p. 105). 



" My attention was next directed to the crevice (about an inch 

 wide) between the stone pavement and the wall ; three of the stones 

 were removed and the soil adhering to the wall carefully examined. 

 To my astonishment I found this a compact mass of cocoons, some of 

 them old and empty, others containing the newly imprisoned larvse, 

 changed in form to a short almost cylindrical-shaped insect of a pale 

 yellow colour, and apparently quite inert. The gardener, who had 

 watched my proceedings, was simply astounded at the discovery, and 

 could scarcely believe they were the recent enemies of his ill-fated 

 Pear-tree. 



"I continued my search along the wall, exposing in all about 

 twelve linear inches, and from so small an area (say eighteen cubic 

 inches) I got about eight hundred cocoons. They were all cemented 

 together in masses, and so firmly attached to the wall that I success- 

 fully cut away portions of the brickwork with the cocoons still 

 attached (fig. 2). None of the cocoons occurred at a greater depth 

 than one and a half inches, while those near the surface were barely 

 covered. While removing the cocoons several specimens of the 

 perfect insect were liberated ; they were very active, and ran about 

 the soil seeking a hiding-place, and making every effort to escape, 

 but, strange to say, did not attempt to use their wings ; the sun had 

 gone down, and this may account for their reluctance in taking flight. 



