286 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



leaf is left, the manner of defoliation being quite characteristic 

 of this species. Low-growing and dwarf varieties are worse injured, 

 as pole beans put out new leaves after the injury has stopped, 

 Life History. The adult beetles hibernate in or near the bean, 

 fields and emerge from April to June according to the latitude. 

 Minute orange-colored eggs are laid near the stem of the plant- 

 just below the surface of the soil, in clusters of six to ten or more, 



and hatch in from 

 five to eight days. 

 The young larvae feed 

 upon the stem and 

 roots, becoming full 

 grown in six or seven 

 weeks. When grown 

 the larva is about 

 three-tenths an inch 

 long, about one-eight 

 as wide, cylindrical, 

 milk-white in color, 



7 / with dark head and 



d e f , 



anal segment, a s 



FIG. 245. The bean leaf-beetle (Ceratoma trifurcata shown enlarged six 

 Foist.): a, adult beetle; 6, pupa; c, larva; d side timeg in Fig 245. 

 view anal segment of larva; e, leg of same; /, egg ? 



a, b, c, enlarged about six times; d, e, f, more The pupa (Fig. 245, 

 enlarged. (After Chittenden, U. S. Dept. Agr.) & ) ig pure white> and 



from it the beetle emerges in five to eight days. Thus, in the Dis- 

 trict of Columbia, the whole life cycle requires six to nine weeks, 

 depending upon heat and moisture. In the North there is prob- 

 ably but one generation a year; in Maryland and Virginia one 

 generation develops in July and another in September; while in 

 the Gulf States there are probably three generations, as beetles 

 are numerous in October. 



Remedies. Spraying with arsenical poisons as for the bean 

 ladybird is the most effectual means of controlling the pest when 

 abundant, but they should be applied early to avoid the poison 

 on beans to be eaten green. Owing to the sluggishness of the 

 beetles they may be handpicked in small gardens. Clean culture 



