Bugs, Cicadas, Aphids, and Scale-insects 171 
belief that the spittle is that of tree-frogs—are small flattish, brownish or 
grayish insects about -J- inch long which occasionally occur in sufficient 
numbers to do some injury to grapes, 
cranberries, or pasture grasses. A grape 
frog - hopper, Aphrophora 4-notata , has 
brown wing-covers with three blackish 
spots on each; another found on grapes 
in the east, A. signoreti, is tawny brown 
clouded with dull white and thickly dotted 
with black spots; the cranberry spittle- 
insect, Clastoptera proteus , which occurs 
on cranberries and blueberries in marshes, 
is black, with two yellow bands on top 
of the head, one in the thorax, two 
oblique stripes on the base of the fore 
wings, and a cross-bar near the tip; C. 
pini is a small shining black species with 
pale yellow head with black band at front 
margin, that occurs on the needles of 
pine-trees. 
Looking like miniature cicadas, but 
belonging to a different family, and really 
more nearly related to the aphids or true 
plant-lice, are the Psyllidae, or jumping 
plant-lice. They are not more than ^ inch long, their hind legs are 
enlarged for leaping, some of them exude honey-dew, as the true plant- 
lice and the scale-insects do, and some make galls on the wings of hack- 
berry and other trees. The best-known and most destructive member of 
the family is the pear-tree flea-louse, Psylla pyricola. This is a minute 
insect measuring only inch long to tip of folded wings, but it often occurs 
in such large numbers in pear-orchards in the northeastern and northern 
states as to destroy extensive orchards. The eggs are orange-yellow and 
laid on the leaves, each egg having a lash-like process projecting from it. 
The young is broad and flat and yellow in color, growing brownish as it 
grows older. The adults hibernate in crevices in the bark and come out 
in spring to lay their eggs. The pests can be killed by spraying the trees 
with kerosene emulsion (see p. 189), immediately after the leaves have 
expanded in the spring. 
A very important and very interesting family is that of the Aphidiidae, 
the plant-lice or aphis-flies (Figs. 244 and 245). The species, of which 
there are many, are all small, J inch being a rarely attained maximum 
length. The most familiar representatives of the family are the tiny, 
Fig. 243.—The spittle-insect, Aphro¬ 
phora, showing stages of froth 
production. (After Morse; en¬ 
larged.) 
