560 EXPERIMENT STATION RECORD, [Vol.38 



the plant, it be called the cranbtTiy viiu-hopper in preference to the name 

 " broad-winged leaf -hopper " by which it has been known. 



Though the pest is said to be essentially one of secondary importance, being 

 found only on vines in an unthrifty or dying condition, due to injury by other 

 insects or drought, it has been taken in every cranberry section of the State. 

 The author has reared the nymphs from egg punctures made in the wood of 

 the swamp blueberry (Vaccininm corymhosum) as well as from cranberry. One 

 generation a year Ls produced, hibernation taking place in the egg stage either 

 on winter flooded bogs or those not flooded at any time. 



Effective remedy consists of the removal of the major insect pests and the 

 general improvement of conditions of vine growth by better cultural methods, 

 such as pruning, sanding, and the application of fertilizers. Reflowing the bog 

 about August 1 for a pei-iod of 24 hours, at which time the nymphs will have 

 hatched and no eggs have been laid by the new adult, is suggested. A light 

 wind will blow the bugs to one shore, where they may be killed by the use of a 

 kerosene-burning spray torch. 



The family Isometopidce as represented in North America, B. H. Gibson 

 (BmI. Brooklyn Ent. Soc, 12 {1917), No. 4, pp. 73-77).— Three species are de- 

 scribed as new and the genus Lidopus erected. 



A key to the species of Dictyophara, E. H. Gibson (Bui. Brooklyn Ent. Soc, 

 12 {1911), No. 3, pp. 69-71). 



The pear woolly aphis, W. M. Davidson {Mo. Bui. Com. Hort. Cal., 6 {1917), 

 No. 10, pp. 390-396, figs. 2). — This paper, based upon the studies of EHosoma 

 pyricola previously noted (E. S. R., 35, p. 463), includes later observations and 

 a brief discussion of control measures. 



In the control work miscible oil, kerosene oil emulsion, and distillate oil 

 emulsion were used at proper strengths with success in controlling aphis on 

 the roots of young orchard trees. Carbon bisulphid injected into the soil in 

 liquid form proved satisfactory both on young orchard trees and in the nursery, 

 although there is some danger to the trees in its use. 



The box elder aphid (Chaitophorus negundinis), R. L. Websteb {Iowa Sta. 

 Bui. 173 {1917), pp. 95-121, figs. jf2).— This account deals largely with biological 

 studies of C. negundinis, a plant louse which quite generally infests the box elder, 

 one of Iowa's common trees. In that State nearly all box elders are infested by 

 the pest and often to such an extent that it becomes a great nuisance. It was 

 particularly obnoxious in southwestern Iowa in 1908 and in 1910 was so abun- 

 dant throughout the State that the box elder foliage was very light. Although 

 the box elder {Acer negundo) is the only plant on which this species is abun- 

 dant, the insect has been recorded by Sanborn on catalpa. It is recorded as 

 occurring from Manitoba and Ontario in the north south to Las Vegas, N. Mex., 

 and from New York in the East and California in the West, though most abun- 

 dant in the States of the Upper Mississippi Valley. It appears to be a native 

 species, having been originally described by Thomas from Illinois in 1878. 



The egg, in which stage the winter is passed, hatches early in the spring just as 

 the box elder buds are ready to burst and on which the young soon begin to feed. 

 Early in June or even late in May normal forms give birth to dimorphs and from 

 then on, during July and August, only the dimorphic forms are generally found 

 on the leaves. The author has observed the dimorphs to molt twice, after which 

 they become normal forms that become active late in August or early in Sep- 

 tember, and when mature give birth to normal forms. It is pointed out that 

 the presence of these dimorphs in midsummer accounts for the fact that for 

 about three months but little damage is done to box elders, the dimorphs re- 

 maining on the leaves, entirely inactive. Due to this fact it is very difficult to 



