FIELD BOOK OF INSECTS. 



CERCOPID^E 



The Frog-hoppers or Spittle-insects get their common 

 names by being broad, squat, hopping creatures whose 

 young live in masses of white froth (Plate XXIII), sucking 

 sap. "The spittle is a viscid fluid expelled from the ali- 

 mentary canal of the insects and beaten up into a froth 

 by the whisking about of the body. What advantage it 

 is to the young insects is hard even to conjecture; it cer- 

 tainly is not known " (Kellogg). Possibly it is a protection 

 against drying out and it is said to harden into a protective 

 shell when the insect molts. 



ClCADELLID^E 



These are the Leaf-hoppers. In the South, the species 

 which attack cotton have been named Sharpshooters and 

 Dodgers. All of our numerous species are small and occur 

 on vegetation of various kinds, especially grasses. Doubt- 

 less the small amount of sap taken by each of thousands 

 of individuals amounts to a great deal per acre of grass- 

 land, vineyard, and orchard. Plate XXIII shows Grapho- 

 cephala coccinea. This family has been called Jassidae. 



CHERMID^E 



The Jumping Plant-lice are usually described as re- 

 sembling miniature Cicadas. The antennae are long and 

 the wings are transparent. Some of the species, especially 

 of the genus Pachypsylla, produce galls, while others feed 

 in exposed situations on the leaves. Probably the most 

 injurious species is the Pear Psylla, Psylla pyricola. It 

 was introduced from Europe about 1832. "Usually the 

 first indication of the pest is the presence of large quantities 

 of honey-dew, secreted by the nymphs, with which the 

 foliage becomes covered, and which attracts numerous 

 ants. When the psyllas are numerous the leaves and fruit 

 become coated with this sticky substance and it even drops 

 from them like rain and runs down the trunk. ["Weeping 

 trees" are caused by a number of different Homoptera.] 

 A blackish fungus grows on the honey-dew and is always a 



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