INSECTS INJURIOUS TO THE APPLE AND PEAR 641 



Life History. The adults hibernate over winter in crevices 

 of the bark and there lay their eggs late in April or early May 

 on the twigs or around the buds. The egg is about one- 

 eighteenth inch long, hardly perceptible without a lens, and 

 orange-yellow in color. It is pear-shaped with the small end 

 drawn out into a long thread, and the larger end is attached to 

 the bark by a short stalk (Fig. 495). The later generations 

 deposit the eggs on the leaves often in rows or bunches. The eggs 

 hatch in two to three weeks and the young nymphs feed on the 

 leaf petioles in the axils of the leaves and later on the leaves, 

 young fruit and tender shoots, from which they suck the sap. 

 The nymph is a peculiar-looking little bug, broadly oval, flattened, 

 of a yellowish color, with crimson eyes, but later becomes reddish 

 with black markings and conspicuous black wing-pads, as shown 

 in Fig. 495. They move very slowly and are frequently quite 

 covered by their own honey-dew. After molting some four or 

 five times, they finally transform to adults in about a month. 

 According to Slingerland there are four generations in New York 

 and probably five in Maryland. 



Control. As the adults hibernate over winter in the bark 

 the treatment advised for the pear leaf blister-mite furnishes the 

 best means of control for the psylla, and winter treatment is 

 absolutely essential for its successful control. Otherwise, the 

 best -time to spray is in the spring just after the eggs have hatched 

 and before the nymphs have secreted much honey-dew. If 

 winter or spring spraying has been neglected, the trees should be 

 thoroughly sprayed with whale-oil soap, 1 pound to 4 gallons, 

 or 10 per cent kerosene emulsion, or dilute miscible oils. Spraying 

 should be done after a shower, which will wash much of the honey- 

 dew off, as the chief difficulty in summer spraying is to reach the 

 nymphs through the thick coating of honey-dew with which thev 

 .are covered. Obviously the spray should be applied with ^on 

 siderable pressure in a coarse spray. 



