140 PEAR. 



quently on the ragged and filthy condition which it acquires, 

 or to enlarge the feeding-ground, and the caterpillars drag 

 themselves about within it by holding on to the threads, and 

 in four or five weeks attain their full growth. 



They then let themselves down to the ground, and bury 

 themselves as much (it is said) as four inches deep, or deeper 

 still, in the earth, in a smoothed cavity, but without spinning 

 a cocoon. Here they change to the perfect sawfly, which, 

 according to recorded observations, may appear in the follow- 

 ing spring, or in the spring next but one to date of going into 

 the ground. 



The figure at p. 137 shows the form of the fly and the 

 neuration of the two pairs of wings. The fly is four to five 

 lines in length of body, that is, from a third of an inch to 

 rather more ; the expanse of the wings somewhat under an 

 inch ; the colour chiefly black, but the abdomen tawny 

 towards the extremity, with a triangular yellow mark in each 

 segment ; ventral segments banded with yellow. The base of 

 the antennae and also the legs yellow ; the four hindermost 

 of the thighs black at base. Wings hyaline, with a broad 

 smoky band below the stigma. In the male the abdomen 

 from the second segment is reddish yellow.* 



Prevention and Eemedies. — The simplest and most effectual 

 plan would be, as with other web-living infestations, wherever 

 the webs are in reach, to cut them off and destroy them with 

 their contents. But a little care must be taken in order to 

 secure all the caterpillars, as on alarm, when nearly full 

 grown, they may let themselves down by their threads, and 

 so escape into the ground. This might easily be prevented 

 by holding a pail below the nest with some sticky fluid in it, 

 soft-soap wash for instance, which would effectually prevent 

 stray caterpillars getting away ; and indeed the best method 

 of operation would be to cut the nest itself and its contents 

 off into the pail of soft-soap wash, and thus make quite sure 

 of none escaping. 



Where the nests are out of reach, syringing soft-soap or 

 soft-soap and paraffin wash at them, so as to sodden the web, 

 would be good treatment, taking care, as before mentioned, 

 to have something placed below to secure such caterpillars as 

 might let themselves down. 



Various observers have mentioned difficulty in rearing this 

 sawfly in artificial circumstances, and perhaps the following 



* For description of fly (imago) see ' British Phytoijhagous Hymenoptera,' 

 by P. Cameron, vol. iii. p. 97 ; and for figure of tij, vol. ii. of same work, 

 plate G ; and of larva and tail processes, plate 12 of same volume. These 

 tigures I beg to acknowledge with thanks as having been copied in my own 

 figure, p. 137. 



