INSECTS INJURIOUS TO BEANS AND PEAS 



311 



like that of the District of Columbia ... as early as October, 

 when in the natural course of events the eggs for a new brood 

 would be deposited in such pods as had cracked open, so as to 

 expose the seeds within." 



" Weevilly " seed should never be planted, as but a small per 

 cent of it will germinate and the vitality of that germinating is 

 deficient. Professor Popenoe showed in experiments at Manhattan, 

 Kan., that only 50 per cent of the infested seed used germinated, 

 that only 30 per cent could ha e grown further, and that even 

 these would have produced plants of little vigor or productive- 

 ness. (Quotations and acts from Chittenden, I.e.) 



Remedies. No methods are known of preventing injury in the 

 field, and all remedial measures must be applied to the insects in 

 the stored seed. As this pecies breeds in the stored seed, it is use- 

 less to hold it over as for the pea-weevil, and the quicker infested 

 seed is treated the better. Either heat, or better, fumigation, as 

 described for the pea-weevil, should be used. When ready to plant, 

 seed should be thrown lightly into water, when that badly infested 

 will float and can be separated and destroyed. 



Other Bean-weevils 



The Cow-pea weevil.* This species may be readily recognized 

 by the two large, raised 

 white lobes at the base of 

 the thorax and the strongly 

 pectinate antennas of the 

 maleasshowninFig. 225, a. 

 The cow-pea is the favorite 

 food-plant of this and the 

 following species, but peas 

 and various sorts of beans 

 are also attacked. This 

 species is a southern form, 

 .but seems to be spreading, 

 incident to the more wide- 



* Bruchus chinensis L'.nn 



FIG. 225. The cow-pea weevil (Bruchus chi- 

 nensis L.): a, adult male; 6, egg; c, young 

 larva; d, front view of head of .same; e, 

 thoracic leg of same; a, much enlarged; 

 6, e, more enlarged. (After Chittenden, 

 U. S. Dept. Agr.) 



