REPORT OF THE CRANBERRY SUBSTATION. 133 



May and very early June, if the winter water is let off early, as it was at 

 the bog where the writer made his tests. The writer observed Scammell's 

 experiments and saw notliing in them to criticize. 



The fruit-worm injury in 1918 was the least of any season in the writer's 

 experience. This, after so severe a winter, seemed surprising. ^ Its injury 

 to the station crop was estimated to be 3 to 4 per cent. 



The Greasy Ctdwarm (Agrotis ypsilon Rott.). 



In a previous report ^ a destructive visitation of the fall army worm 

 (Laphygma frugiperda S. & A.) on cranberry bogs, following closely and 

 evidently somehow caused by the removal of the winter flowage in mid- 

 July, was noted. This season a similar visitation by the greasy cutworm 

 (Agrotis ypsilon Rott.) occurred in August on a large part of the Wankinco 

 bog, the bog having been flowed from early June to July 10. The blackish 

 worms m their feeding dropped a litter of uneaten leaf fragments onto 

 the sand under the vines. They were first seen about August 10, many 

 being then considerably grown, and they disappeared on the bog about 

 August 24. They seemed to be cannibals when confined in tightly closed 

 «ans in numbers together, for they became rapidly fewer under such con- 

 ditions without any other evident reason. They pupated in confinement 

 in late August and early September, and the moths emerged from Sep- 

 tember 18 to October 2. 



The writer thinks there maj^ be several more species that on occasion 

 will infest cranberrj^ bogs, bared of their winter flowage in midsummer, in 

 this way. Scammell's explanation that the moths of the fall army wonn 

 seem to be attracted to bogs recently bared of the flowage, and there lay 

 their eggs in preference to bogs from which the flowage was removed at 

 the normal time, is probably correct for that insect and other species as 

 well. Observations made by the writer in 1917 on a bog in Plymouth 

 support this opinion. The winter flowage was let off this bog August 10, 

 and a few days later great numbers of moths were found among the vines 

 on all parts of it. The moths were of the three following species, most of 

 them being of the first two : — 



1. Nomophila noctuella S. V. 



2. Drasteria erechtea Cram. 



3. Autographa falcigera var. simplex Gu. 



These moths were not noticed on anj' bog that had the winter flowage 

 off early. No worm infestation developed later where the moths appeared. 

 The cranberry may not be a food plant of anj^ of the three species, or the 

 moths may have laid most of their eggs before they came onto the bog. 



1 Bui. No. 180, Mass. Agr. Expt. Sta., 1917, p. 227. 



2 Bui. No. 180, Mass. Agr. Expt. Sta., 1917, p. 232. 



