150 



LEAF-BEETLES. 



"The adults feed on leaves, flowers or pollen, but the larva;, 

 which are white and slender, usually feed in the roots and stems 

 of plants. One of our most common forms, (Diabrotica vittata 

 Fab.), is known as the "striped cucumber-beetle," and is yellow 

 with black stripes on the wing-covers. It feeds on all kinds of 

 cucurbit vines, and on many other plants as well ; it does injury 

 by eating into the stem of the young shoot at or below the sur- 

 face, where it has a tendency to hide during the middle of the 

 day. The larvae, (Fig. 154), live in the main roots under ground, 

 making short galleries, which, if numerous, weaken or even kill 

 the plants. The beetles winter as adults. A free use of tobacco 



Pipr. 154-. — Diabrotica vittata. Fab. — After Division of Entomology, U. S. De- 

 partment of Agriculture. 



dust around young vines or other injured plants is usually pro-' 

 tective, though in some localities the farmers resort to " driving." 

 Thev do this before the middle of the day, sowing air-slaked lime 

 with the wind, and this seems to be sufficiently ofl:'ensive to the 

 winged insects to induce them to leave for fields to the leeward, 

 where they of course become doubly injurious unless also driven 

 off. Planting an excess of seed to distribute the injury is common 

 practice, and so is starting the plants in baskets and setting them 

 cut when well established and able to resist injury. 



"Melon and other cucurbit vines should always be plowed 

 out, raked up, and destroyed as soon as possible after the crop is 

 off, to destroy any larvae that may then be in the roots." 



