Bugs, Cicadas, Aphids, and Scale-insects 171 



belief that the spittle is that of tree-frogs are small flattish, brownish or 

 grayish insects about ^ inch long which occasionally occur in sufficient 

 numbers to do some injury to grapes, 

 cranberries, or pasture grasses. A grape 

 frog -hopper, Aphrophora ^.-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 



FIG. 243. The spittle-insect, Aphro- 

 phora, showing stages of froth 

 production. (After Morse; en- 

 larged.) 



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, \ inch being a rarely attained maximum 

 length. The most familiar representatives of the family are the tiny, 



