INSECTS ATTACKING THE PEAR, AND THEIR CONTROL 1035 



FIG. 314. THE 

 PEARPSYLLA: 

 ADULT 



the winter are quite distinct from the summer adults. They appear 

 early in spring and deposit their eggs in protected places on the 

 bark. The eggs hatch in about three weeks, and 

 the little larvae, or nymphs, at once begin to suck 

 the juices from the young leaves and twigs. A 

 favorite place . for the young nymphs is in the 

 axils of tho leaves and at the bases of the fruit 

 stems. Within two or three days after hatching 

 they cover themselves with hoiieydew, which 

 finally becomes very abundant. The leaves be- 

 come stunted and sometimes fall, and the fruit 

 ceases to grow in size and may drop prematurely 

 if the work of this first brood is continued by 

 the later broods. In long-continued attacks the 

 trees may become almost defoliated, and the new 

 leaves, if they appear, are generally few in 

 number and pale in color. With the injury caused by the draft 

 on the sap of the tree, there is joined an external disfigurement 

 of both leaves and wood due to the copious secretion, of honey- 

 dew by the psylla, which serves as food for the sooty fungus. 

 Growth of this fungus 

 soon gives the wood a 

 smutty, discolored appear- 

 ance and darkens and 

 stains the leaves. If the 

 attacks of psylla are se- 

 vere, the trees go into 

 win for in a weakened state 

 and succumb much more 

 readily to low tempera- 

 tures than do uninjured 

 trees. Renewed attacks, 

 year after year, so lessen 

 the vitality of the trees 

 tli at they become unpro- 

 ductive. 



Treatment During seasons when it is superabundant the psylla 

 is greatly feared, and most growers fail to protect their orchards. 



FIG. 315. THE PEAR PSYLLA: EGGS 



