144 ECONOMIC ENTOMOLOGY 



yellow tipped with black, long and tapering; body covered with a 

 powdery substance. Winged females with black thorax and red ab- 

 domen, honey-tubes long and black. Two small tubercles at end of 

 abdomen; the late winged forms are migrants and have a black patch 

 on abdomen, black bands across last segments of abdomen, and black 

 spots on sides. Egg-laying females lemon-yellow, mate with migrant 

 winged males. In this species also the males are produced on the 

 secondary and the females on the primary host. After the third 

 summer agamic generation this species deserts the apple for the 

 plantain, but returns in autumn. (Consult ''Apple Tree Insects of 

 Maine," Circ. 31, Bur. Ent., U. S. Dept. Agr.) 



Sweet Cherry Aphis {Myzus cerasi Fab.). — Eggs oval and black, 

 laid around the buds and on bark of twigs and branches, hatching in 

 late April. Stem mother globose and glossy black. First brood 

 wingless viviparous, later broods winged and wingless viviparous; the 

 winged form with head, thorax, cornicles and cauda black, and abdomen 

 dark green to dark brown migrate to Lepidium where several broods of 

 dark brown, wingless viviparous forms and darker winged forms are 

 produced. The latter return to cherry when they and other resident 

 winged forms produce viviparous females which are fertilized by 

 migrant winged males from Lepidium. No males are produced on 

 the cherry. Six to 14 generation are produced during the season in 

 the Niagara district. Controlled most successfully in early spring, 

 just before the buds burst, by spraying with lime sulphur and Black 

 Leaf 40 (Ross, 48//? Rep. Out. Ent. Soc, 1917). 



Clover Aphis (Aphis bakeri Cowan). — See above. 



Green Peach Aphis {Myzus persicce Sulz). — This general feeder is our 

 most common greenhouse species. Under glass it reproduces vivi- 

 parously from year to year. At first the young lice are pink, but next 

 generation is bright green. Migration in third generation to garden 

 crops (where it has been known as Rhopalosiphum diantki Schr.) 

 returning in autumn to peach. 



Currant Plant-louse {Myzus ribis L.).- — A small yellowish plant- 

 louse causing a curling and bhstering of the leaves of currants with 

 red discoloration of the upper surface. Wingless female light green 

 and mottled; body covered with capitate hairs, and with two rows 

 of spots on mid-dorsal surface. Winged forms darker and abdomen 

 crossed by several bands. Migrates to Stachys and Galeopsis (Gillette). 



