156 ECONOMIC ENTOMOLOGY 



white lines and dots between the eyes; a series of six whitish spots 

 on front margin of prothorax, two whitish hnes on mesothorax form- 

 ing a letter H; three dots on scutellum; strongly convex above; front 

 rounded; wings thin and uniform, folded close about the body; legs 

 slender, hindmost larger; three or four generations each year. Adults 

 may live 14-30 days. Hibernates. 



Eggs. — Autumn eggs laid in September under epidermis of apple, 

 summer eggs under epidermis of petioles of apple, clover, etc.; hya- 

 line, cylindrical. 



Nymphs. — ^Light green; feed on under side of leaves causing white 

 spots, most injurious in May-June; five nymphal stages covering 22 

 days. 



Control. — Spray in spring with a mixture of Black Leaf 40 and whale- 

 oil soap; collect adults by driving tanglefoot screens along the rows 

 in bush-fruits. 



Rose Leaf -hopper {Empoa roses Linn.). — ^Leaves of rose bushes and 

 apple trees are often badly infested with the Rose Leaf-hopper, and all 

 stages of growth may be readily found. Eggs are laid in July, and 

 eggs are again laid in the fall beneath the bark of young wood of roses, 

 blackberry, and strawberry runners, where they stay over winter. 

 Migration from the roses occurs in June. Controlled by lime-sulphur 

 and Black Leaf 40 during the early nymph stages (Consult Bui. 148 

 Oregon Ag. Exp. St.) 



ClCADID^ 



Periodical Cicada {Cicada septendecem Linn.). — (Consult Bull. 71, 

 Bur. Ent., U. S. Dept. of Agr.) Often called the Seventeen-year Locust. 

 Adults damage orchards and nurseries by making egg punctures in 

 the twigs. 



Adult.— ^ne and one-fourth inches long, black; abdomen banded 

 with red; eyes red; veins red at base and along front margin; June; 

 duration about 30 days. Dwarf forms also occur. 



Eggs. — Each female lays 300 to 500 eggs in punctures made by 

 ovipositor in twigs and stems; eggs hatch in 6 to 8 weeks. 



Nymphs.- — Burrow in the ground, feeding on juices of roots and 

 humus of soil; moult probably 4 or 6 times at intervals of 2 to 4 

 years. In the spring of the seventeenth year they emerge and moult, 

 changing to adults. A race or sub-species having a 13-year period 



