PEA AND BEAN INSECTS 



77 



become winged. The winged forms (Fig. 51) migrate to 

 their summer food plants but the insect is capable of breeding 

 the entire season on the plants on which it passed the winter. 

 Throughout the summer the aphids 

 reproduce parthenogenetically, all the 

 individuals being females. Whenever 

 the host plants become crowded, winged 

 forms are produced that migrate to fresh 

 feeding grounds. The full-grown wing- 

 less viviparous female is about yV i^^ch 

 in length and blackish in color (P'ig. 52). 

 In the last nymphal stage of the winged 

 form the abdomen is ornamented with 

 five to seven pairs of white pulverulent 

 spots (Fig. 53). In the fall the winged 

 forms fly back to their winter host 

 plants and there produce young that develop into wingless, 

 egg-laying females. These are joined by winged males and after 

 mating they deposit eggs in the crevices around the buds. 



The bean aphis can be killed by spraying with " Black Leaf 

 40" tobacco extract, 1 part in 100 parts of water in which 

 enough soap is dissolved to give a good suds. 



Fig. 53. — Last nymphal 

 stage of the winged 

 viviparous female bean 

 aphis (enlarged). 



The Garden Flea-Hopper 



Halticus citri Ashmead 



This small black plant-bug resembles the cucumber flea- 

 beetle in size, form and in its habit of jumping when disturbed. 

 The female is dimorphic. In one form the wings are fully 

 developed and in the other they are short and lack the mem- 

 branous portion at the end. The long-winged form (Fig. 54) 

 is 3^2 inch in length, black in color, with the thorax and wings 

 covered with small tufts of yellowish scale-like hairs ; the tip 

 of the cuneus has a white spot. The legs and antennse are 



