I/O AN INTRODUCTION TO 



:ne men venth agamic general i. >n a 



:ni;cd males, Tlu-M- tly to the plum-trees and mate 



with the wingl< \hich are already then-. Soon 



r this th lepOSlt n the smaller twig^ ami bran* 



of the plum, in and around the angles formed by the buds and t\\ 



from one to thr. 



If it should be ]>roven that this -pecie- can winter only on plum, 

 on of plum and hop culture would be adxisablc. But 

 further observations are needed before we are warranted in advising 

 the destruction of plum-trees in the hop-growin. MS. But 



urge the careful destruction of all Aphids on plum-trees early in 

 the season. The most practicable way of doing this is by spraying 

 with a strong solution of soap or with kerosene emulsion. < 

 Chapter XIV.) 



Family V. PSYLLID/E.* 



('/// mping Plant-lice. ) 



The Jumping Plant-lice are comparatively small insects; our 

 more common species measure only 3 or 4 millimeters in 

 length ; and our largest species, the giant, comparatively speak- 

 ing, measures only 6 mm. and has a wing-expanse of 12 mm. 

 They resemble somewhat the winged Aphids in appearance ; but 

 they look more like miniature Cicades i Fig. 

 They are, however, closely allied to the Aphids ; but 

 they differ from them in the firmer texture of the 

 body, in the stouter limbs, in having the hind 

 fitted for jumping, and in the 9- or lO-jointcd an- 

 tcnnaj. The antenn.e are peculiar also in being 

 armed at the tip with two bristles, or less commonly 

 aVed^ 7 *' with one "The rostrum is short, three-jointed, and 



placed almost between thi h fits into 



a grooved -pace. Both Lfe always winged in the adult ; the 



win. are ample, and, while often trail-parent , are much thicker 



than the wings, and furnished with stout curving veins, which 

 encl< I the tip." < I'll! 



The Psyllidaj subsist entirely upon the juices of plants; many 

 species form galls. But it is rare that any of them appear upon culti- 

 -1 plants in sufficient numbers to attract attention, except incase 

 of the Pear-tree Psylla. 



* Psyllidac, Psylla : /;//</ (0i',U<r), a flea. 



