ENTOMOLOGY IX OUTLINE HEMIPTERA. 



51 



FIG. 49. Buffalo tree- 

 hopper (Ceresa bv- 

 balus). 



under leaves or rubbish, and the best preventive method to be applied 

 against them is to thoroughly clean the vineyard and its neighborhood 

 of all loose rubbish and burn it. By this means the next season's crop 

 of the pest can be greatly reduced. 



They are very destructive in meadows, and it is stated that these 

 insects destroy from one fourth to one half of the grass that springs up 

 annually. They are more numerous than any other insect, except, 

 perhaps, the aphids. 



Family MembraeidaB (Tree-hoppers). In this family we find some 

 of the most grotesque forms in the animal kingdom. This is the typical 

 family of the suborder Homoptera. Its members are 

 of every conceivable form, and are described by Prof. 

 Otto Lugger as " arched, compressed, depressed, hump- 

 backed, spindle-shaped, pointed at both ends, inflated, 

 hemispherical or conical, and besides this they are 

 furnished with an endless variety of superficial 

 attachments." They live principally on trees and 

 bushes, and all possess great leaping powers, hence 

 their common name. They are usually not sufficiently numerous to be 

 destructive and have therefore little economic value. 



Family Psyllidse (Jumping Plant-lice). Members of this family 

 resemble the cicadas in general build, but are much smaller, being from 

 a sixth to an eighth of an inch in length. They differ from the aphids 

 in being of a more solid texture, with stouter legs, the 

 hinder pair being especially strong and fitted for 

 jumping. In their adult form, both sexes are winged. 

 A peculiarity in some of the species of 

 this family is the bifurcated antennae. 

 In these the feelers are split and end 

 in two bristle-like points. Some of 

 these species exude a honey-dew, and 

 in this respect approach the aphids. 

 The commonest and most destructive 

 member of this family is the pear-tree 

 Psylla (Psylla pyricola). This is a 

 very small insect, not over a sixteenth of an inch in length, but it 

 often occurs in such quantities as to do enormous damage to the pear 

 orchards. 



Family Aphididse (Plant-lice). This family is closely akin to the 

 foregoing, and in some of its many species is known to nearly every 

 one; to all who have endeavored to grow flowers or vegetables, or who 

 have noticed trees at all. It is a very extensive family, and includes 



FIG. 50. Pear-tree 

 Psylla) Psylla pyri- 

 cola). Enlarged. 



FIG. 51. Larva of 

 Psylla pyricola. 

 Enlarged. 



