82 PROTECTION OF PLANTS, 1917-18 



2. Common Fruit Aphids. 



Apple Bud or Oat Aphis (Aphis avenae Fab.). — See above. 



Green Apple Aphis (Aphis mali Fah. = A. pomi DeG.) — This aphis collects 

 usually on the tips of tender shoots, on the under surface of the leaves, and when 

 abundant attacks the developing fruit. Winters on twigs as black shining eggs 

 which hatch just before leaf buds open; l-12th inch long, pear-shaped; bright 

 green; black, slender cornicles; inhabits the apple throughout the season; winged 

 females occur during summer. Causes curling of the leaves to some extent, those 

 of young trees suffering most. Several (10-15) generations in a season, and each 

 generation shorter than three weeks, and each mother produces 70 young. 



Rosy Apple Aphis (Aphis sorhi Kali = A. malifoliae Fitch = A. pyri Boyer) — 

 This shade-loving aphis collects around the flower buds, the developing fruits 

 and on the under side of the leaves. It causes nearly all the curling of the leaves 

 and the "cluster-apples." Larger than preceding; l-9th inch long. Wingless 

 females blue; honey-tubes yellow tipped with black, long and tapering; body 

 covered with a powdery substance. Winged females with black thorax and red 

 abdomen, 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 generations this species deserts the apple for the plantain, 

 but returns in autumn. 



(Consult "Apple Tree lusects of Maine," and Circ. 81, Bur. Ent. U.S. 

 Dep. Agr). 



Cherry Aphis, (Myzus cerasi Fab.) — Shining black; long, slender honey tubes; 

 antennae not as long as body, smoky, cauda pointed, black and hirsute. Is a pest 

 of the cherry. Migrates to wild pepper grass. 



Clover Aphis (jiphis Bakeri Cowan) — See above. 



Green Peach Aphis (Myzus persicae Sulz). — ^This general feeder is our most 

 common greenhouse species. Under glass it reproduces viviparously from year to 

 year. At first the young lice are pink, but next generation is bright green. Migra- 

 tion in third generation to garden crops (where it has been known as Rhopalosi- 

 phum dianthi Schr.) returning in antumn to peach. 



Currant Plant Louse (Myzus ribis L.) — ^A small yellowish plant-louse causing 

 a curling and blistering of the leaves of currants with red discoloration of the 

 upper surface. Wingless female light green and mottled; body covered with cap- 

 itate hairs, and with two rows of spots on mid-dorsal surface. Winged forms 



