INSECTS INJURIOUS TO TOBACCO 



223 



more than one-twentieth inch long, light brown in color, with 

 a dark band across the wing-covers. A few of them could do 

 but little damage, but they soon 

 increase in numbers, so that they 

 swarm over the leaves and injure 

 them badly. Similar injury is done 

 to potato, egg-plant, and tomato, 

 and the beetles also feed on horse- 

 nettle, nightshade, and Jamestown 

 weed. 



Life History. -The eggs are laid 

 in the soil and the larvae feed upon 

 the roots of common weeds, such 

 as the nightshade and Jamestown 

 weed. The larva is delicate, thread- 

 like and white, except the yellow- 

 ish head, and about one-eighth 

 inch long. It pupates in the soil. 

 When the beetles become very nu- 

 merous the larvae sometimes de- 

 velop on the roots of tobacco, but 

 rarely do serious damage. The 

 life history has not been deter- 

 mined exactly, but the full life 

 cycle seems to occupy about a 

 month, so that there are probably 

 several generations in a year. 



Control. Inasmuch as the larvae 

 develop on the roots of the weeds 

 mentioned, it is evident that they 

 should be kept down by thorough 

 cultivation. Where the beetles ap- 

 pear, the plants should be sprayed 

 or dusted with Paris green, or 

 probably better, arsenate of lead, 

 the same as for the horn-worm. 



FIG. 159. Tobacco leaves 

 damaged by Epitrix par- 

 vula. (After Howard, U. 

 S. Dept. Agr.) 



Dipping the plants in arse- 



