170 Bugs, Cicadas, Aphids, and Scale-insects 



known to economic entomologists as special pests of grasses, growing grain, 

 grapes, roses, etc. The injury is caused by the draining away of the 

 sap of the plant by the host of little sucking-beaks thrust into its leaves 

 or stem. Among the notorious destructive species are the destructive leaf- 

 hopper, Cicadula exitiosa, ^ inch long, brownish, which often injures 

 seriously the winter wheat of the southern states. Also the various 

 grape-leaf hoppers, which cause the leaves of grape-vines to wilt and turn 

 brown and prevent the formation of full grapes; one 

 of these, Erythroneura vilis, is about inch long, 

 crossed by two blood-red bands and a third dusky 

 one at the apex. I have seen millions of individuals 

 of Erythroneura comes (Fig. 242) in the great 3300- 

 acre vineyard of the Vina Ranch in the Sacramento 

 Valley of California. These leaf-hoppers hibernate 

 in the vineyard or about its edges under fallen 

 leaves and rubbish. Probably the best remedy for 

 them is to keep the vineyards as clean as possible, 

 or at least to burn up in the winter any accumulated 

 rubbish. The rose leaf-hop- 

 per, Typhlocyba rosce, is 

 often abundant on rose- 

 bushes, and also on apple- 

 trees. The eggs are laid in 

 the summer, and the young 

 develop through the summer 

 FIG. 242. and fall) hibernating as 



FIG 241 -The celery leaf-hopper, Cicadula 4 -Uneata. aduks under leaveg Qr rub . 



(After Lugger; natural size indicated by line.) 



FlG. 242. Two vine-hoppers, at left Erythroneura bish. A common leaf-hop- 

 vulnerata, on right E. comes. (After Forbes; much p er o f grass-fields is Diedro- 



cephala mollipes, ^ inch long, 



spindle-shaped, grass-green above, pale yellowish below, with black lines 

 across the face and top of head, and the fore wings with bluish veins and 

 yellowish edges. 



Occasionally one finds frothy, spittle-like masses adhering to the stems 

 of weeds or shrubs in which may be found imbedded one or more odd- 

 shaped, squat, slant-faced insects from ^\ inch to \ inch long (Fig. 243). 

 These are the young they have no wings, only wing-pads or, if very young, 

 not even these of the spittle-insects or frog-hoppers, family Cercopidae. 

 The spittle is a viscid fluid expelled from the alimentary 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 certainly is 

 not known. The adult frog-hoppers this name is derived from a popular 



