290 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



dock, upon the leaves of which it occurs commonly in large num- 

 bers. Shepherd's purse, pigweed, the " burning bush "(Euony- 

 mus europoeus and atropurp urus), and the snowball bush are also 

 commonly infested. 



Life History. The life history was first described most inter- 

 estingly by Dr. Fitch in his 13th Report* and has since been 

 confirmed by Osborne and Sirrine.f The eggs are laid in the fall 

 around the buds of the wahoo or " burning bush " (Euonymus 

 atropurpurus), and possibly upon the snowball. The first gen- 

 eration or two multiply upon these plants and then spread to 

 common weeds such as shepherd's purse, pigweed, dock, etc., 

 during the latter part of May and early June, from which they 

 again migrate to beans when that crop is available. During 

 the summer the aphids multiply upon these food-plants vivipar- 

 ously, i. e., by giving birth to live young, all being females, as is the 

 rule with aphids; but about the middle of September, in Iowa, 

 winged males and females migrate back to the wahoo. 



Description. The wingless females are about one-tenth an 

 inch long, pear-shaped, sooty black, frequently marked with 

 pruinose whitish dots along each side of the back. The antennae 

 are about half the length of the body, yellowish-white, except 

 toward the tips and the two basal segments, which are black. 

 Honey tubes short, scarcely half as long as from their bases to 

 tip of abdomen. Tail half as long as the honey tubes. 



The winged females are glossy-black, one-twelfth an inch 

 long to the tip of the abdomen and twice that length to the tip 

 of the closed wings. The abdomen lacks the white spots of the 

 wingless females and pupae. Legs are black, except shanks, 

 which are whitis-h with dark tips. Otherwise the winged form 

 resembles quite closely the wingless form. The black color 

 and white spots on the abdomen of the wingless females and 

 pupae will readily distinguish the species from other aphids on 

 beans. 



Control. Spraying with dilute kerosene emulsion has proven 

 the best means of combating the pest according to Osborn and 

 Sirrine, diluting the stock solution fifteen times, or so the spray- 

 ing mixture will contain about 5 per cent of kerosene. It seems 



* Fitch, 13th Report on the Noxious, Beneficial and other Insects of the 

 State of New York, Trans. N. Y. State Agr. Soc., 1869, p. 495. 



t Osborn and Sirrine, Bulletin 23, Iowa Agr. Exp. Sta., p. 901, 1894. 



