62 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



apple, cherry, Primus andersoni, wild thorn (Crataegus tomentosa) and 

 willow. 



Control.— As the young feed upon vegetation allowed to grow in 

 or around the orchards, it is important to practice clean culture, begin- 

 ning not later than the last of April and continuing throughout the 

 summer. The grass and weeds along the fences should also be destroyed. 

 Pruning out the punctured branches during the winter will do much to 

 reduce the spring brood. 



Natural Enemies.— Two hymenopterous parasites. Cosmocoma sp. 

 and Tricliogramma ceresarum Ashm. 34 have been reared from the eggs 

 of the buffalo tree-hopper. Neither of these, however, have been 

 reported in this State. 



JASSIDvE (Family) 



LEAF-HOPPERS 



The leaf-hoppers are rather small insects and especially active, 

 being able to jump so quickly that they are sometimes called "sharp- 

 shooters." They resemble somewhat the tree-hoppers but do not 

 have the curious raised prothorax extending back over the abdomen. 

 The hind tibiae are armed below with two rows 

 of spines. The members of the family are 

 exceedingly numerous and may be found upon 

 many kinds of vegetation. 



THE APPLE LEAF-HOPPER 



Empoasca mail LeBaron 35 

 (Fig. 51) 



Description.— The adults are light yellow- 

 ish-green with lighter spots on the dorsum of 

 the head and a row on the front margin of the 

 pronotum. TJie length is about | inch. The 

 nymphs are very pale and distinguished 

 from the adults by the absence of fully- 

 developed wings. The eggs are white, elon- 

 gate, slightly curved and about 1-40 inch 

 long. 



Life History.— The winter is passed in 

 both the egg and adult stages. The winter 

 eggs are laid in the fall and are inserted just 

 beneath the bark of two- or three-year-old 

 wood. Small swellings on the surface mark 

 the position of the eggs. Hatching begins in 

 the early spring and the young at once begin 

 to feed upon the leaves. On reaching ma- 

 turity in about a month the summer broods begin to deposit eggs, which 

 are inserted in the softer tissues of the petioles and larger veins of the 



"Insect Life VII, pp. 12-13, 1894. 



"The rose leaf-hopper, Empoa rosw (Linn.), is quite abundant on roses and often 

 does considerable damage to the foliage of apple and pear trees in this state. 

 (Fig. 52). Mr. Leroy Childs also reports this species injurious to fruit trees in Oregon. 

 Specimens for the illustration were received from him. 



Fig. 51.— Adult of the 

 apple leaf -hop per, Em- 

 poasca mali LeB. Greatly 

 enlarged. (After Forbes) 



