INSECTS INJURIOUS TO TOBACCO 



213 



except the yellowish head, and about one-eighth inch long. It 



pupates in the soil. When the beetles 



become very numerous the larvae some- 



times develop on the roots of tobacco, 



but rarely do serious damage. The 



life history has not been determined 



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 cul- 

 tivation. Where the beetles appear, 

 the plants should be sprayed or dusted 

 with Paris green, or probably better, 

 arsenate of lead, the same as for the 

 horn- worm. Dipping the plants in 

 arsenate of lead, 1 pound to 10 gal- 

 lons of water, just as they are set, has 

 been found to afford very satisfactory 

 protection in Connecticut. 



The Tobacco Stalk-worm * 



Professor W. G. Johnson found this 

 species, also known as the Corn-root 

 Web worm, to be a serious pest to grow- 

 ing tobacco-plants in southern Mary- 

 land, where it seems to have been a 

 tobacco pest for a good many years, 

 and it has also been noted in Delaware. 



The Injury. The injury to tobacco FlG - 179. T o b a c c o leaves 



is described by Professor Johnson as Holrlf u"s . 



follows: "The uninjured tobacco had 



a leaf spread of from ten to twelve inches. A few rods beyond, 



where the soil was not so gravelly and better, we found the larvse 



* Crambus caloginosellus Clem. Family Crambidce. See p. 161 and Bul- 

 letin 20, n. s., Div. Ent., U. S. Dept. Agr., pp. 99-101, 1899, 



