ANNUAL REPORT, 1941 37 



THE CRANBERRY STATION 

 East Wareham, Massachusetts 



H. J. Franklin in Charge 

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



Hill Fireworm {Tlascala finitella (Walker)). One and a half acres of the Summit 

 Cranberry Company's bog at Greene, R. I., replanted in the spring of 1941, were 

 seriously infested in the hills by this insect in mid-July. Vines planted there in 

 1940 were also attacked but less severely and mere along the runners lying on the 

 sand than in the hills. These infestations were curbed completely by spraying 

 and dusting heavily with rotenone materials. 



About 50 acres of heavy vines of the Burrage bog at South Hanson, Mass., 

 were found to be infested throughout by this insect from July 12 to August 12, 

 1941. The worms were everywhere rather plentiful there in the thicker clusters 

 of vines during the latter half of July, being mostly in their tubes of frass and 

 silk well down among the vines but considerably above the bog floor. They did 

 considerahle, but not severe, damage by devouring under leaves and blossoms. 

 The superintendent of the bog said it had been similarly attacked by this pest 

 in 1940. 



Many of the worms were about full grown on July 19, 1941. A few were still 

 present in their tubes among the vines of the Burrage bog on August 12. The 

 largest were about thirteen sixteenths of an inch long, with the head black, the 

 cervical shield black with a much-broken pale yellow stripe along its front margin, 

 the body dark brown, striped lengthwise on the back and sides, except toward 

 the hind end, with about eight narrow and broken pale yellow stripes, these being 

 most conspicuous toward the front end. The first moths to appear in confine- 

 ment emerged August 8 and more came out from August 10 to 20. Many live 

 pupae remained on November 18. 



Some of these worms were found in their tubes among the foliage of cultivated 

 swamp blueberry bushes at the station. 



Cranberry Root Grub {Amphicoma vulpina). Some of these grubs were sent 

 to the Japanese and Asiatic beetle laboratory at Moorestown, New Jersey, in 

 January 1941, to have their susceptibility to the milky disease organism deter- 

 mined. Mr. C. H. Hadley, in charge of the laboratory, reported later as follows: 



With further reference to my letter of January 10th regarding tests to 

 determine the susceptibility of the cranberry root grub, Amphicoma 

 vulpina, to the milky disease organism, we have completed the prelim- 

 inary tests with the material which you sent me in January. Negative 

 results were obtained both by injection tests and feeding tests with the 

 type A milky disease organism, Bacillus popilliae. No evidence of milky 

 disease development was observed either by macroscopic examination or 

 upon microscopic examination of the blood of the injected individuals. 

 Neither was there any indication of development of the organism in larvae 

 which had been given opportunity to feed in infected soil. We must, 

 therefore, conclude that this species of larva is not susceptible to milky 

 disease infection. 



Late in the spring, one of the cranberry growers started further tests of paradi- 

 chlorobenzene as a control for this pest, applying the chemical with a fertilizer 

 spreader at the rate of 1200 pounds an acre and covering it at once with about an 

 inch of sand. His plots were examined late in August and nearly all the grubs 

 were found to have been killed, even where flooding foi frost protection and for 

 insect control had been done soon after the treatment was applied. This treat- 

 ment probably will be useful in special situations, as on bogs that cannot be 

 treated with cyanide because they drain into public water supplies, or perhaps 

 on bogs with a surface soil too dense to take in the cyanide solution readily. 



