394 Report of the Department of Entomology of the 



insects feed only on the old wood, a condition that occurs frequently 

 with the nymphs, the berries are dwarfed, as shown in Plate XII, 

 fig. 2, d. Sometimes the berries shrivel or grow one-sided, but as a 

 rule they remain miniature berries and ripen as such; but where 

 bugs feed on the new branches, or a number of them on one old branch, 

 the berries shrivel up and the branch dies. In cases where the insects 

 feed on old wood, or wood of the previous year, all the new branches 

 beyond the feeding point may produce dwarfed berries. It has been 

 observed in the field that where one insect is feeding alone on new 

 growth, this branch will wilt and change color. The plants usually 

 start new buds below the point where the insects are feeding. 



The amount of injury to the vines is considerable, as can readily 

 be measured by the amount of fruit the affected plants produce. 

 There is always a very characteristic difference between injured and 

 uninjured portions of bogs, which could not be better illustrated 

 than in the Brown bog at Calverton, L. I. In this planting there is 

 a ten-foot drainage ditch which cuts a tract of Early Blacks into two 

 parts. The portion south of the ditch has been infested for several 

 years, while very few of the insects have reached the area north 

 of the ditch. In the fall of 1911 the difference between these two 

 tracts could be distinguished at a distance of a quarter of a mile. 

 The affected side was brown and unhealthy in appearance, while 

 on the opposite side of the ditch the vines were normally green and 

 vigorous. The differences were noticeable in 1912, although, after 

 the flooding operations in July, the affected portion threw out new 

 growth and improved rapidly in appearance by fall. 



host plants. 



The host plants listed by collectors of this species convey the 

 impression that atra is a general feeder, but so far as observed by 

 the writers this insect finds its subsistence only on the cranberry. 

 Careful observations have failed to detect this species feeding on 

 other marsh plants. After flooding of the bog the insects have been 

 collected from weeds and willows on the sides of the marsh, but at 

 no other season of the year have they been observed on these same 

 plants. 



enemies. 



The ladybird beetle (Hippodamia 13-punctata) and the soldier bug 

 (Coriscus inscriptus) occur in abundance in bogs overrun with atra. 



