208 MASS. EXPERIMENT STATION BULLETIN 280 



stone fruits, Macrosporium leaf-blight of carrots, black-rot of cauliflower, 

 bacterial-wilt of cucurbits, onion "blast," Cytospora canker of blue spruce, 

 hollyhock rust, bacterial-spot of delphinium, angular leaf-spot of cumcubers 



THE CRANBERRY STATION 



(East Wareham, Massachusetts) 

 H. J. Franklin in Charge 



The arrangement of 1930, whereby the extension services of Plymouth and 

 Barnstable Counties maintained a service for the cranberry growers of the two 

 counties, was continued during the most active part of the summer season of 

 1931 with very satisfactory results. 



Injurious and Beneficial Insects Affecting the Cranberry. (H. J. 



Franklin). Numerous special comparative spraying tests with the black-headed 

 fireworm (Rhopobota vacciniana), in which nicotine sulfate and potash fish-oU 

 soap, nicotine sulfate and potassium oleate soap, nicotine sulfate and penetrol, 

 nicotine sulfate and lignin pitch-tannin mixture, pyrethrum extract, and pyre- 

 thrum soap were used, showed very clearly the marked superiority of a pjaethrum 

 soap spray over all the other materials tried. Moreover, these tests brought 

 out the fact that it pays to use 6 pounds of the commercial pyrethrum soap to 

 100 gallons of water instead of the 5 heretofore advocated. This amount of the 

 soap was also found advisable in tests with the false blossom leafhopper (Ophiola 

 striatula) . The results obtained by many experienced growers in commercial 

 practice during the season fully justified the results of these spraying experiments. 



Tests with pyrethrum extract, pyrethrum soap, and nicotine sulfate and 

 potash fish-oil soap against the red-striped fireworm {Gelechia trialhamaculella) 

 confirmed previous results in showing that the nicotine sulfate spray is much 

 the most efficient against this pest. 



Tests showed that a pyrethrum soap spray (6 pounds in 100 gallons of water) 

 is about as effective in killing moths of the cranberry girdler {Cravibus hortuellus) 

 as is the nicotine sulfate and soap spray (nicotine sulfate 1 qt., soap 4 lbs., water 

 100 gals.) commonly used to treat the black-headed fireworm. 



In all the many tests made with it, pyrethrum extract was found so nmch 

 inferior to pyrethrum soap in its toxic properties that its use seems seldom 

 advisable for any cranberry pest. 



Extensive dusting tests with various cranberry insects were carried out, the 

 dust used being pyrethrum and a gypsum carrier of 300-mesh fineness. ^Yhile 

 these tests should probably be continued, the results obtained seemed to show 

 plainly that such a dust is a satisfactory control for the false blossom leafhopper. 

 It also killed the moths of the black-headed fireworm and so possibly may help 

 as a control for that pest. 



The general results of spraying with nicotine sulfate and soap to control the 

 cranberry fruit worm {Mineola vaccinii) on various bogs were observed carefully 

 and found to be not only encouraging but in some cases striking. 



It is worth noting that the opinion is becoming pronounced among cranberry 

 growers that the spread of the false blossom disease has been notably checked 

 since treatments have been applied to control the leafhopper vector. 



The life history of a species of Tiphia which is the main parasite of the cran- 

 berry root grub {Amphiconta vulpina) was largely worked out. 



