156 MANUAL OF VEGETABLE-GARDEN INSECTS 



or less serious oiit})reaks have occurred in southeastern Penn- 

 sylvania and in New Jersey. In New York the insect has been 

 troublesome in the upper Hudson River Valley and in Ontario 

 on Pelee Island in Lake Erie. Its wild food plants include a 

 number of solanaceous weeds, such as ground cherry, James- 

 town weed, buffalo bur and horse nettle and it has also been 

 recorded as infesting cocklebur. Eggplant is sometimes at- 

 tacked and there is at least one record of injury to tomato. 

 Early potatoes are more subject to injury than late varieties. 

 The adult (Fig. 90) is a snout-beetle, about -J- inch in length, 

 bluish gray in color with the head and scutellum black and 

 with a black spot on each side near the 

 ^^^•^ ^^^ ^^ margin at the junction of the prothorax 

 1 ^^^Mi /^ ^^^^^ ^^^^ hn^e of the wing-covers. The 

 ^^^^^^^S^ ground color of the beetle is black, its 



blue-gray color being derived from a 

 thick covering of narrow scales. The 

 beetles appear in the field in spring 

 and feed for a time on the stems of 

 the potato which they puncture with 

 their beaks. The female inserts her 

 eggs singly in the stalk or branches 

 and sometimes even in the leaf petioles. 

 In ovipositing, she first liollows out a cavity with her beak 

 and then turning around places the egg in the puncture. 

 The egg is oval, yellowish white and about 4V inch in length. 

 The eggs hatch in a week to ele^Tn da} s and the young 

 grub burrows down through the pith several inches and then 

 turning about retraces its course. When nearly full-grown, 

 it eats out the entire pith for some distance. When mature 

 the larva is f to ^ inch in length, yellow^ish white, with the 

 head brownish. Legs are lacking. The presence of the 

 grubs is indicated by a wilting and dying of the leaves, 

 wdiile the stem may remain green for some time. Several 



Fig. 90. — The potato 

 stalk-weevil (X G|). 



