Treatment 



FLOODING 



On bogs that cannot be refiooded. — Prevention: let ofF the winter water 

 before May 20. 



On bogs that can be reflooded — Flood for ten hours at night as soon as the net 

 count (p. 3) shows it is necessary. 



SPRAYING OR DUSTING 



Spraying with 6 pounds of lead arsenate or 3 pounds of 50 percent wettable 

 DDT in 100 gallons of water, 300 gallons to the acre, is effective while the 

 worms are small. 



Dusting with 50 pounds of 10 percent DDT to an acre is advocated. 



BAITING — See page 26. 



Armyworm 2 9 



This notorious cutworm infests bogs after late draining of the winter 

 water oftener than the others. It may begin its attack within eight days after 

 the removal of this flood if the water is let off any time between about May 

 20 and about July 10. It never harms a bog drained early unless it is very grassy 

 or is reflooded for ten days or longer in late May. 



The moths seem to fly at times with the prevailing winds for many miles in 

 great numbers and alight in a body to lay their eggs in a place favorable to 

 the development of the worms. This accounts for the sudden appearance of this 

 insect in regions remote from any known source of infestation. A few of the 

 moths appear every year over most of the area in which it occurs, but this 

 does not explain the sudden great invasions that come from time to time. It 

 was very abundant in the Cape cranberry region in 1914 and 1919. 



Armyworm outbreaks nearly always start in the Southern States. They are 

 noted there by the Bureau of Entomology of the United States Department 

 of Agriculture, which predicts their spread into the North. They are more 

 common after cold, backward springs. 



The armyworm feeds mostly in low meadows and among rank'growing grasses. 

 Its movement in armies is not normal, but follows an exhaustion of food which 

 compels it to spread to other places. 



Distribution and Food Plants 



This originally was an American insect, but now it inhabits most of the world. 



It prefers grasses, both wild and cultivated, and the grains, such as barley, 

 corn, millet, oats, rye, and wheat. When pressed with hunger a little, it at- 

 tacks alfalfa, apple, bean, beet, cabbage, cauliflower, clover, cranberry, cucum- 

 ber, flax, lettuce, parsley, pea, pepper, strawberry, sweet potato, watermelon, 

 and other plants. 



Character of Injury 



The worms nip off the cranberry leaves more freely than blossom worms 

 and spotted cutv.;orms do, sometimes nearly defoliating the vines. They also 

 commonly cut new uprights nearly off, so that they break over and hang by a 

 thread. They feed mostly at night and on cloudy days, but also travel and 

 feed a good deal in bright weather. 



^ Cirphis unipuncta (Haw.). 



[32] 



