i8o DESTRUCTIVE INSECTS. 



the spray, the few worms left will form a sufficient nucleus 

 for a large and very destructivve second or third brood ; in 

 these localities the best that can be advised at present is to 

 supplement the poison spray with the old banding system. 



Various methods of trapping the worms when they are about 

 to spin their cocoons have been practised with some degree of 

 success. The most simple and as effective as any is to wrap 

 a band of straw, or two or three folds of old burlap around 

 the trunk of the tree. Put on the bands about the middle of 

 June and examine and destroy the cocoons found in them 

 every ten days until about September ist when they need not 

 be examined again until after the fruit is gathered. 



To use the poison spray the most effectually one must un- 

 derstand that it is necessary to fill the blossom-end of each 

 apple with poison within a week after the blossoms fall, for 

 this is where the little apple-worm gets its first few meals, and 

 it is practically our only chance to kill it with a spray. 

 Watch the developing fruit after the petals fall, and be sure 

 to apply the poison before the calyx lobes close (as shown in 

 Figs. 244 and 245), for while the falling of the blossoms is the 

 signal to begin spraying, the closing of these calyx lobes a week or 

 two later is usually the signal to stop spraying. 



The Pear Psylla {Psylla pyricola), one of the jumping 

 plant-lice, has recently attained first rank as a pear pest in 

 the eastern United States, and it occurs westward to the 

 Mississippi River. It attacks only the pear-tree and has 

 nearly ruined some pear orchards in New York ; trees of all 

 ages and varieties are attacked. Most of the damage is done 

 by the nymphs (Fig. 248), which are only about one-tenth of 

 an inch in length, but they often appear in incredible num- 

 bers, and congregating in the leaf-axils or on the fruit stems 

 they soon sap the life of trees to such an extent that but little 

 growth is made and the fruit sometimes drops when half- 

 grown. The nymphs secrete large quantities of a sweet, 

 sticky liquid, called "honey-dew," which spreads over the 

 branches and leaves, sometimes even dripping from the trees. 

 All through this honey-dew a black fungus grows, so that the 

 bark of badly infested trees h3.s a black, sooty appearance ; 

 this is usually good evidence at any time of the year that a 

 pear-tree has suffered from the psylla. The adult insects (Fig, 



