INSECTS INJURIOUS TO POTATO, ETC. 221 



which it does to asters and related plants. It is uniformly 

 black, without polish, and its length varies from a little more 

 than a quarter to half an inch. It is 

 well distributed east of the Rocky 

 Mountains, and does most injury be- 

 tween the Atlantic States and Texas. 

 Its time of appearance is more or less 

 coincident with the blossoming of the 

 goldenrod, on which it is a familiar 

 object, from June until October. As 

 a rule it appears later than other ' 

 species. It is one of the worst insect 

 enemies of potato and beet, and is 

 also destructive to carrots, beans, cab- 

 bage, corn, mustard, aster, clematis F'g- I4i.-Biack Mister beetle. 



Enlarged. (Author's illustration, 



and other plants. For remedies see u. s. Dept. Agr.) 

 page 68. 



The Potato Stalk Weevil (Trichobaris trinotata Say.). — This 

 is an important insect enemy of the potato, and a common 

 species almost everywhere east of the Rocky Mountains and 

 south of New England. Its larva works normally in the stems 

 of horse nettle, ground cherry, and jimson weed, in most fields 

 where these plants are allowed to grow. 



The habit of this insect of attacking potato has been known 

 since 1849. Since then injuries inflicted by it have attracted 

 considerable attention, periodically and locally, and there is 

 reason to believe that it is often present and doing damage, 

 though undetected, in potato fields, where the insect itself has 

 never been seen. Its habit of living in the stem in its larval 

 condition, and the small size of the beetles, together with 

 their trick of dropping from the plants when disturbed, is 

 accountable for injury so often escaping notice. 



The potato stalk weevil (fig. 142) is a small snout-beetle, 

 about 1/6 inch in length. Its real color is black throughout. 



