CRANBERRY INSECT PROBLEMS. 



41 



with a sweep-net 40 to 50 may be caught 

 in four or five sweeps. 



The beetle (fie. 38) measures slightly 

 less than one-fourth inch and is shin- 

 ing mahogany brown. The usual dura- 

 tion of life is 1 month to weeks, and 

 during this time the eggs are laid singly. 

 or in masses of as many as 50, just be- 

 neath the surface of the soil or on litter 

 under the vines. 



Treatment. 



37. — Cranberry rootworm : 

 Pupa. Much enlarged. 



Flooding the bog to control this in- 

 sect is of little avail unless it be done 

 when the beetles are feeding on the foliage in the latter part of 

 June and early July. Since this time is also the beginning of the 

 blooming period, a good deal of injury would result to the crop by 

 reflowing, and such treatment can not be recommended unless it is 

 desired to rest the bog by destroying the bloom. During the larval 

 11 nd pupal stages the rootworm can survive prolonged reflowing, and 

 no dependence can be placed upon spring or fall reflows to exter- 

 minate it or even lessen its numbers appreciably. 



Invigorating the vine growth by sanding on muck bottom and 

 applying commercial fertilizer on sandy bottom promises good re- 

 sults in sustaining the vine growth, but should be accompanied by 



spraying, for which pur- 

 pose one of the arsenicals 

 may be used. Arsenate of 

 lead is a satisfactory insecti- 

 cide and should be applied 

 at the rate of 3 pounds of the 

 paste, or half that amount 

 of the powder, to 50 gallons 

 of water. Burning of the 

 foliage has not been noted 

 where 2 pounds of fish-oil 

 soap have been included. 

 The arsenical also may be 

 used in combination with the 

 Bordeaux and soap spray. 

 At least two applications 

 should be made, one about 

 June 25 and the other as 



Fig. 38. — Cranberry rootworm: Adult, or beetle. ,111 1 r. n 



Much enlarged. soou as the bloom has fallen. 



