INSECTS ATTACKING CUCURBITACEOUS PLANTS. 809 



practiced by most large growers. Paris green may be mixed 

 with air-slaked lime or plaster at the rate of one pound of poison 

 to seventy-five pounds of plaster, and the mixture sifted upon 

 the plants. This, of course, cannot be used before the plants come 

 up, and when the beetles are extraordinarily abundant much 

 damage will often result to the plants in spite of the application 

 of poison. Lead arsenate mixed with water at the rate of three 

 to five pounds in fifty gallons of water and sprayed or sprinkled 

 upon the plants is usually an excellent remedy. 



In order to keep the beetles wholly away from the plants it 

 is necessary to cover them with frames of netting. A barrel hoop 

 may be cut in two equal parts and fastened together at right 

 angles, the ends set in the ground, and the frame covered with 

 ndlting. The ends of these semicircular hoops may be fastened 

 to another hoop lying horizontally in order to make a portable 

 frame, and the whole covered with netting. Boxes and various 

 other forms of wood may be designed into protectors for this 

 purpose, but they are chiefly for use in the home garden, and 

 must be placed over the hills before the beetles appear. In some 

 cases it is possible to drive away the beetles by a frequent dusting 

 of the plants with fine coal ashes, air-slaked lime, or insect powder, 

 and some growers use trap plants and practice burning all old 

 plants and rubbish in the field after the crop is harvested. 



The Southern Corn Root Worm or Twelve-Spotted 

 Cucumber Beetle. 



Diabrotica xii-punctata Oliv. 



This insect is not usually included in a Kst of insects injurious 

 to cucurbitaceous plants, but it has been so abundant in certain 

 fields which have come under our observation that surely con- 

 siderable damage must have been done by it, and for that reason 

 it is listed here. 



For many years the adults have been known to feed upon a 

 large number of plants, including nearly all of the common vege- 

 tables and some of the fruit blossoms and field crops. The larvae 

 are a serious pest of corn roots in the Southern States, and also 

 attack rye, millet and garden beans, sometimes doing considerable 

 damage. 



