INSECTS INJURIOUS TO POTATOES AND TOMATOES 287 



but a good one, is to rake up the vines and burn them as soon as 

 the potatoes have been dug. As this insect also feeds upon the 

 Jamestown weed, horse-nettle, and other weeds of the Nightshade 

 family, or Solanaccce, they should be kept cut down very closely. 

 When the grubs are noticed in the plants, a good allowance of fer- 

 tilizer will do much to quicken growth and thus enable them to 

 mature a crop. 



The Stalk-borer * 



This species may well be called the stalk-borer, for it not only 

 tunnels the stalks of potatoes being often called the potato stalk- 

 borer and tomatoes, but frequently infests corn, cotton and a long 

 list of garden crops, grains, grasses, flowering plants, and various 

 common weeds. Apparently the latter, such as ragweed, cockle- 

 bur and the like, are its normal food plants, and when they are 

 destroyed or where more tender cultivated plants are near by, 

 it attacks whatever is available. Two or three nearly related 

 species have very similar habits. 



The adult moth (Fig. 211) is a fawn-gray or mouse color, with 

 the outer third of the fore-wings paler and bordered within by a 

 whitish cross-line. 



Life History. The eggs are laid in the fall on the stems of 

 weeds and grasses, in masses of fifty or sixty, near the ground, 

 They are about one-fiftieth inch in diameter, circular, grayish 

 in color, with radiating ridges. They hatch in late May in 

 southern Minnesota and the young caterpillars at once commence 

 to mine small galleries in the leaves of the food plants, soon 

 riddling the leaves. In a few days they work down to the bases 

 of the leaves and enter the stalks, which they tunnel out and not 

 infrequently leave one plant and migrate some little distance 

 before entering another. Infested plants are readily recognized 

 by the wilting of the parts above the larva, the work in corn 

 being particularly noticeable and having given the local name 

 of " heart-worm." The larva become full grown about the 

 first of August. They are readily recognized by the peculiar 



* Papaipema nitella Gn. Family Noctuidce. 



