THE INSECT WORLD. 



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wing-covers. It feeds on all kinds of cucurbit vines, and on 

 many other plants as well, doing injury by eating into the stem 

 of the young shoots at or below the surface, where it has a ten- 

 dency to hide during the middle of the day. The larvae live in 

 the main roots underground, making short galleries, which, if 

 numerous, weaken or even kill the plant. The beetles winter as 

 adults. A free use of tobacco dust around young vines or other 

 injured plants is usually protective, though in some localities the 

 farmers resort to ' ' driving. ' ' They do this before the middle of 

 the day, sowing air-slacked lime with the wind, and this seems 

 to be sufficiently offensive to the 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 a common practice, and so is starting the 

 plants in baskets and setting them out 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 pos- 

 sible after the crop is off, to destroy any larvae that may be then 

 in the roots. 



An allied and equally common species, feeding as an adult 

 upon a great variety of plants, is the D. i2-pimctata, or "12- 

 spotted Diabrotica." This is somewhat larger than the preced- 

 ing, with a more oval body, and has twelve black spots on the 

 greenish-yellow wing- covers. The larva feeds on the roots of a 

 variety of plants and becomes injurious to corn in the Southern 

 States. There are two broods, and the beetles winter in the 

 adult stage. No direct remedy is known, but good cultivation 

 and a liberal application of stimulating fertilizers is advisable to 

 enable the corn-plant to resist and outgrow attack. Clean cul- 

 ture is the greatest essential, and this of itself will do much to 

 reduce injury. 



The ' ' corn-root Diabrotica' ' of the Western and Central 

 States is of a uniform, pale-green color, named D. longicornis, 

 from its long antennae, and its larva has proved a serious pest to 

 corn. The complete life history of the insect is known, and as it 

 winters in the egg state in corn-fields, simple rotation is all that 

 is necessary to destroy the species. It can never become injuri- 

 ous unless corn follows corn year after year, and even a single 

 year without corn serves to completely rid a field of the pest. 



