PEAR INSECTS 



55 



g-alls but emerge later and form other blisters; af- 

 fected leaves turn yellow and drop, thus injuring 

 the tree. 



Control — Spray trees in fall or spring with 

 lime-sulphur, i gallon to lo or 12 of water. 



The pear psylla ^^ (Psylla pyricola) 

 Order^Hemiptera. Manual, p. 156 



A very fluctuating pest introduced from Europe 

 upon young pear trees about 1832; very injurious 

 in central and western New York and along the 

 Hudson; the orange-yellow eggs are deposited in 

 creases in the bark mostly before the buds burst; 

 the eggs hatch usually during the first two weeks 

 of May; the nymphs suck juices from leaves and 

 stems of young fruit ; they secrete great quantities 

 of honey-dew in which a fungus thrives and forms 

 a black coating all over the branches ; the nymphs 

 mature in about one month and the adults appear ; 

 there may be four broods in a season ; the adults of 

 the last brood winter over in the crevices of the 

 bark. 



Control — Scrape rough bark from trees and 

 spray in November or December or March or early 

 April with nicotine sulphate, y^ pint to 100 gallons 

 and 5 pounds of soap ; miscible oil may also be used 

 at the rate of i gallon to 15 of water; spray on 

 warm days when the temperature is not freezing; 

 spray last of April or early May as buds are burst- 

 ing with lime-sulphur at winter strengths to kill eggs. 

 Spray for nymphs with '' black-leaf 40," % pint to 

 100 gallons with 5 pounds of soap; practice clean 

 culture. 



35 Slingerland— Cornell Univ. Expt Stat, Bull. 44. 

 Hodgkiss— N. Y. State Expt. Stat, Bull. z^y. 



