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 vitis , is about J 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 
and fall, hibernating as 
Fig. 241. 
Fig. 242. 
Fig 2 41 -The celery leaf-hopper, Cicadula 4-lineata. adults under leaves or ~ rub . 
(After Lugger; natural size indicated by line.) 
Fig. 242.—Two vine-hoppers, at left Erythroneura bish. A common leaf-hop- 
vulnerata , on right E. comes. (After Forbes; much per 0 f grass-fields is Diedro- 
enlarged.) 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 y 1 ^ inch to J 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 
