34 BULLETIN 1032, U. S. DEPARTMENT OF AGRICULTURE, 



plats E, F, G, and H, but particularly on H, it was noticed that the 

 berries were generally much larger and the vines of a brighter green 

 than those on the other plats. Wherever this spray solution was used 

 it seemed to have a fertilizing or stimulating effect on the vines, 

 making them grow more luxuriantly and produce larger sized berries 

 than they otherwise would have done. 



RECOMMENDATIONS FOR CONTROL. 



REFLOWING. 



As recommended by Scammel/^ reflowing, where it is possible to 

 do it properly, will doubtless be as effective in controlling the black- 

 head fireworm on the Pacific coast as elsewhere. While no experi- 

 ments were performed along this line on the Pacific coast, yet for the 

 benefit of those growers who may be able to equip their bogs for 

 reflowing and wish to employ this method of control, it might be 

 stated that the proper time to reflow for the fireworm is when the 

 majority of the larvae of the first brood are about full grown, as at 

 this time they can be more easily and quickly killed than in any other 

 stage.^^ On the bogs in the vicinity of Seaview, Wash., the majority' 

 of the larvae of the first brood are full grown near the middle or 

 latter part of May, but if the bog is winter flowed, i. e., covered 

 with water in the wintertime, this date would vary according to 

 the date this winter flood was drawn from the bog. In reflowing, the 

 water should completely cover the vines and be held there for at least 

 48 hours in order to kill the greatest number of larvae. Any grass or 

 other objects projecting above the surface should be removed so that 

 the larvae can not crawl up to the tops and thus escape the flood. 



SPRAYING. 



Spraying with a solution of 40 per cent nicotine sulphate and 

 water, with soap as a spreader, has been found to be the most effec- 

 tive method of controlling the blackhead fireworm on the Pacific 

 coast. 



How TO Prepare the Nicotine Sulphate Spray. 



Any nicotine solution containing 40 per cent of nicotine sulphate 

 is suitable in the preparation of this spray, and any kind of soap 

 free from uncombined oils or greases may be used as a spreader. 

 The proportions found most effective against the fireworm are : One 

 part of 40 per cent nicotine sulphate to 800 parts of water, with 2 

 pounds of soap to each 50 gallons of the liquid. Solutions containing 

 a greater proportion of nicotine sulphate than 1 to 800 will do no 



'^ Scammol, H. B. Cranberry Insect Problems and Suggestions for Solving Them. 

 r. S. Dept. of Agi-., Farmers' Bulletin 860, p. 7-8. 1917. 

 "Ibid, p. 8. 



