PEAH PSYLLA 157 



with soft soap or whale-oil soap, made the consistency of thick 

 paint. To this is added some crude carbolic acid, an ounce to 

 each gallon of the wash. 



Another borer which is worth mentioning here is the shot- 

 hole or pin borer, a small, cylindrical insect of the size of the lead 

 in an ordinar^^ pencil. It makes many small holes in the trunk 

 and main branches, but, so far as known, never attacks a 

 thoroughly healthy tree. If this insect is found, therefore, it is an 

 indication that the trees have been damaged in some other way, 

 and the cause of and remedy for this injury should be 

 investigated 



INSECTS ATTACKING THE PEAR 



The pear is attacked by much the same list of insects as the 

 apple. The San Jose scale is even more pai-tial to it than to the 

 apple, the codling moth attacks it, so does the curculio, and the 

 canker worm is by no means averse to a pear diet. Of course 

 the treatment for all these insects is the same as when they 

 attack the apple. Two other insects, however, which have not 

 been mentioned may be given here. 



Pear Psylla. — This insect prefers the pear and it frequently 

 becomes so serious as to practically ruin an orchard. Cases are 

 known where men were actually driven to cut down their pear 

 trees because of the difficulty of keeping the psylla in check. 



Life Historjj. — The adult insect is very small indeed, perhaps 

 a tenth of an inch in length, and is likely to escape notice en- 

 tirely unless a systematic search is made for it. The adults are 

 very active, jumping and flying readily, and from this are often 

 called "jumping lice." They pass the winter in this stage, in 

 cracks and crevices or under scales of bark on the trees. With 

 the first warm weather the eggs are deposited, principally upon 

 the twigs. The young soon hatch and begin feeding, which 

 they do by sucking the juice of the tree, attacking principally 

 the leaf stems. The insect gives off a "honey dew" similar to 

 that of the aphis, which coats the whole tree, trunk and all, 

 with a shiny, and later a blackish, varnish. So abundant do 

 they become by successive broods, that the trees are seriously 



