22 BULLETIN 1032, U. S. DEPARTMENT OF AGRICULTUEE. 



time throughout the summer. The ladybird beetles, with few excep- 

 tions, are beneficial insects; the adults of this species have been 

 observed to feed readily on the larvae of the blackhead fireworm in 

 captivity, and in the field doubtless consume large numbers of this 

 insect. 



CONTROL EXPERIMENTS. 



Since most of the cranberry bogs on the Pacific coast can not be 

 provided with a sufficient supply of water for use in control work, 

 insect pests on these bogs should be combated largely by the applica- 

 tion of insecticides in the form of a liquid spray. This method seems 

 especially desirable against the fireworm after a study of its habits 

 and methods of feeding. It may also be necessary to do more or less 

 spraying for certain fungous diseases at various times throughout 

 the season, and some of the dates for these applications may corre- 

 spond to a great extent with the time of application in the control 

 of the fireworm. The grower, therefore, can combine the materials 

 used for the control of the fireworm with those necessar}'' for fungous 

 diseases whenever the times for these two applications coincide, and 

 thus save the expense of separate applications. 



All the control experiments against the blackhead fireworm were 

 arranged, therefore, so as to include tests under actual bog conditions 

 of several methods of spraying the eggs, larvae, and adults with a 

 number of promising insecticides, both with and without spreaders, 

 at various times throughout the season. These sprays were applied 

 by the types of nozzles shown in figures 12, 13, and 14, all the tests 

 being so planned as to shed some light on questions concerning the 

 number of applications, the best materials to be used, the amount of 

 spray material which should be used per acre, and the most effective 

 manner of applying it. 



MISCELLANEOUS SPRAYING EXPERIMENTS. 



In Table 3 is given an outline and the results of the miscellaneous 

 spraying experiments conducted on Howe vines on the Portland-Sea- 

 view Cranberry Co. bog at Seaview, Wash., in 1919. Very similar 

 experiments were performed on this bog in 1918, but the severe infes- 

 tations previous to that season had so reduced the bearing power of 

 the vines that few blossoms were set in 1918, and the results therefore 

 were not wholly dependable. They showed, however, a decided in- 

 crease in control by the use of insecticides combined with spreaders, 

 such as soap or glue, as compared with the same insecticides applied 

 Avithout the addition of these Avetting agents. They also suggested 

 that a solution of 40 per cent nicotine sulphate, used at the rate of 1 

 part to 1,000 parts of water, with the addition of fish-oil soap at the 

 rate of 2 pounds to 50 gallons and applied at the rate of about 300 



