LEAF-BEETLES. 



151 



It is also a common and very effective practice to cover young 

 plants with a mosquito-netting, held in position by a slight frame. 



Such beetles are not unfrequently found in the flowers of 

 apple or plum, and they are there for no good purpose. 



An allied and equally common species feeding upon a great 

 variety of plants as an adult, is the D. 12-punctata, Oliv. or "12- 

 spotted Diabrotica,'' (Fig. 155). This is somewhat larger than 

 the preceding, with a more oval body, and has tw^elve black spots 

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

 of plants, and becomes injurious to the corn in the Southern 

 States. There are two broods, the beetles wintering in the adult 



Fig. 155. — Diabrotica 12 punctata, Oliv. — After Division of Entomology, U. S. 

 Department of Agriculture. 



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 culture is 

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

 injury. 



In the Western and Central States a third species (Fig. 156) 

 is found, the "Corn-root Diabrotica," (D. longicornis Say), 



