REPORT OF CRANBERRY SUBSTATION FOR 1915. 31 



siderable area on the entire bog being thus affected. The vines showing 

 this condition appeared entirely like those of the same variety (Early 

 Black) on about ten acres of a bog a few miles away, the other varieties of 

 which (Late Howe and Matthew) showed no such trouble. The Early 

 Black berries picked on this other bog this season showed poor keeping 

 quality both in storage and shipment. It perhaps may be inferred from 

 this that lime favors the development of some disease that is peculiar 

 to the Early Black variety. 



The experiments with fertilizers to determine the possibility of stimu- 

 lating and increasing the "setting" of cranberry blossoms, discussed in 

 the last annual report of the substation (page 102), were continued and 

 extended, one Early Black and one Late Howe plot (each of eight square 

 rods) being treated in addition to the two areas used last year. On the 

 station bog the blossoming period of the Early Black variety extended 

 from July 1 to July 20, and that of the Late Howe from July 9 to July 26. 

 The fertilizer was applied to the two Early Black plots on July 7, and 

 was washed in by a good rain the following day. The Late Howe plots 

 were treated on July 14, but no rain of any consequence followed the 

 application until the 19th. The fertilizer was used on all these plots at 

 the following rate per acre: 160 pounds of nitrate of soda + 400 pounds of 

 acid phosphate + 200 pounds of high-grade sulfate of potash. The Early 

 Black plots and their checks were picked on September 17 and 18, and 

 the Late Howe on October 14, no very distinct advantage in quantity of 

 fruit, on the whole, being shown by the fertilized areas. The berries from 

 three of these plots were put in storage tests, and all showed an impaired 

 keeping quality in comparison with the fruit from the checks. 



Insects. 



The black-head fire-worm caused about its normal amount of injury 

 during the season. The loss caused by the fruit worm was considerably 

 more than in either 1913 or 1914, but not as great as in some years. The 

 false army worm (Calocampa nupera Lintner) has not been generally in- 

 jurious for several years and was not much in evidence in 1915. The 

 army worm {Heliophila unipunda Haworth), which caused so much appre- 

 hension on account of its great abundance in 1914, dropped out of sight, 

 as did also the forest tent-caterpillar {Malacosoma disstria Hiibner) and 

 the apple-tree tent-caterpillar (Malacosoma americana F.), both of which 

 had been tremendously abundant in the cranberry region, as elsewhere, for 

 several previous seasons. 



A spanworm commonly seen on cranberry bogs in July, known to 

 science as Ahbotana clemataria Sm. and Abb., ^ was reared successfully, 

 the moths emerging between the 20th and 27th of May from pupae formed 

 between the 9th and 25th of July, 1914. One of the reared moths laid a 

 batch of 432 eggs about May 30. The eggs were green when first deposited, 

 but during the period of incubation they changed first to red, then to 



1 Identified by Mr. August Busck of the Bureau of Entomology, United States Department 

 of Agriculture. 



