26 



Life History. 



The beetles deposit their eggs singly, burrowing beneath the soil, 

 laying, according to Doctor Sniith,*^ from 12 to 20 eggs. The result- 

 ing larvae feed upon the roots of various grasses and possibly weeds 

 and other vegetation. They are mostly full grown by fall, and 

 burrow below the frost line, where the winter is spent. With the 

 coming of spring the grubs ascend toward the surface and enter the 

 pupa stage, from which in from 10 to 30 days, varying with the 

 temperature, the beetles develop and attack the grape and other 

 plants, as stated. • There is thus but one generation each year, the 

 principal injury of the insect being done during the 3 or 4 weeks of 

 its life as a beetle. 



Treatment. 



The rose-chafer is an exceedingly difficult insect to combat suc- 

 cessfully. When the insect occurs only in moderate numbers, arseni- 

 cals will be reasonably satisfactory; but when it occurs in swarms, 

 the plants are reinfested as fast as the insects are killed. It is pos- 

 sible, however, that a hea^^^ application of arsenate of lead, say 5 to 6 

 pounds to 50 gallons of w^ater or Bordeaux mixture, will largely pro- 

 tect the vines, and this plan should be tested by vineyardists con- 

 fronted with this pest. Very thorough applications should be made 

 upon first signs of the insects and repeated as necessary. Many 

 different substances have been applied to vines to render them obnox- 

 ious to the beetles, but none of these has proved to have any special 

 value. Perhaps the method most generally relied upon is picking or 

 jarring the beetles from the vines. In the latter work an umbrella- 

 shaped frame with a canvas or oil cloth covering, with a can of kero- 

 sene at the bottom, is frequently used, being held under the vines, 

 which at the moment are sufficiently shaken to cause the beetles to 

 fall. Jarring or hand-picking must be done every morning, or, 

 better, twice a day, during periods of severe infestation. 



The numbers of this insect may be considerably lessened by re- 

 stricting its breeding grounds. In vineyards on sandy or light soil 

 especial care should be taken to keep the rows and surroundings free 

 from weeds and grass, upon the roots of which the larvae feed. Sandy 

 meadow lands in the vicinity of vineyards should be broken up and 

 cultivated to annual crops, and in this work the cooperation of vine- 

 yardists throughout a neighborhood is especially important. 



Bagging grapes as soon as the fruit has set is often practiced, and 

 afl^ords protection not only against further injury from the rose- 

 chafer, but also from the grape berry moth, the grape curculio, and 

 fungous diseases of the fruit. 



INSECTICIDES.'' 

 ARSENICALS. 



Arsenicals, applied in the form of a spray, are effective against 

 the grape root-worm, the grape berry moth, the grape curculio, 

 the grape leaf-folder, and other insects which devour the foliage 



a Bui. 82, N. J. Agrl. Exp. Station (1891). 



6 For a more extended account of insecticides, see Farmers' Bulletin 127, U. S. 

 Dept. of Agriculture, by C. L. Marlatt. 

 284 



