CAPE COD CRANBERRY INSECTS 49 



HAIRY WORMS. 



These eaterpiliars lia\t' copious liair over imicli of the l)ody. Tliey are open 

 feeders, never sewlni>- the lea\es together. They are like eutwornis in the 

 number and arrangenient of their legs and in tiieir gait. Several kinds of 

 hairy worms oeeur in small numbers on the bogs, but only three need notice 

 here. They may be distinguisiied by the following: 



Table of Worms. 



Head red white-ma rked tussock moth.^^ 



Head not red 1 



1. Working in late spring and early summer gypsy moth (p. 49). 



Working in late sunnner Datmia sp.'" 



Gypsy Moth.'' 



This Old M'orld species brought into Massachusetts in 18()8 did not infest 

 the Cape cranberry region seriously till 1913. During 1913 and 1911 it in- 

 creased vastly there, lieconiing an important cranberry pest. It did much harm 

 on the bogs till 1920 when it decreased and was treated much more effectively 

 by the growers. Its important natural enemies brought from abroad should 

 check it largely hereafter, but it must be regarded as a permanent bog pest 



for it will have years of abundance. .a'-; 



-¥'■ 



l)if<friliiifioii and Food Flaiifs. 



This jiest ranges widely through Eurasia and North Africa. In our coun- 

 try it still is confined to New England and areas in Ohio, New York and New 

 Jersey. It has hundreds of food plants. 



Character of lujiirii. 



The young worms couuuonly attack the terminal buds first, eating all but 

 the outer scales ((ig. 3-5) and often causing great loss before the grower 

 knows his bog is infested. As the new growth develops, the caterpillars greed- 

 ily devour the leaves, flower buds and blossoms (fig. 36) and often sever the 

 new part of the stem (fig. 37). They attack the old foliage severely when 

 they are very abundant and have destroyed the more attractive new growth 

 and sometimes even gnaw hark from the vines. 



The work of this insect on cranberry vines is much like tliat of the false 

 armyworni in all stages. This is true of no other pest. 



An infestation of two first-stage worms to the square foot often develops 

 so as to destroy nearly all the new growth, and one larva to the square foot 

 usually reduces the crop materially. 



Bogs usually do not yield well till the second year after severe injury by 

 this pest, but vigorous vines often do so the next year. 



.55. Hemerocampa leiuostigma (S. & A.). A beautiful caterpillar sometimes rather abundant 

 on dry bogs but never very harmful. 



56. These worms sometimes defoliate small patches of vines in late August but never do 

 much harm. 



57. Porlheiria dispar (L.). See U. S. Dept. Agr. Bui. 1093, 1922. 



