INSECTS AFFECTING OHIO SHADE TREES 1^9 



The winter is passed in a partially grown condition, maturity 

 being rieached and egg development completed early in June. 

 Usually about the middle of June the young appear. 



In the author'sexperience winter applications of the stronger 

 insecticides commonly used against scale insects have /proved un- 

 successful in furnishing a control, in fact the insects seemed to be 

 little harmed by the applications. It may be found, however, that 

 kerosene emulsion containing 20 to 22 percent kerosene will bring 

 about the desired results. This, however, cannot be given as an 

 authoritative statement. The emulsion used in the experiments, 

 against the pest was only 14 percent kerosene, as it was not deemed 

 safe to use a stronger mixture. Subsequent trials have 'demon- 

 strated, however, that a hard maple will stand, during the dormant 

 period, applications of an emulsion containing 20 percent kerosene 

 and in some instances will recover from the effect of applications 

 containing 40 percent kerosene. See Plate 4, Fig 2. The hard 

 maple is more liable to injury from the application of strong emul- 

 sion than is the soft maple. 



The adult females of this insect are 

 1 he rLlm Bark L,ouse, ,, , , . . . ,_, 



Gossytariasfuria yioA^^r. the most conspicious forms. (Plate 



3, Fig. 2.) The following description 

 is taken from Memoir 8, N. Y. State Museum. "They maybe seen- 

 clustered along the under side of the smaller limbs, usually beside 

 a crack or crevice in the bark, and presenting a general resemblance 

 to a growth of lichens. The full grown viviparous females are about 

 ■ 1-10 inch long just before giving birth to their young, oval in out- 

 line and vnth slightly pointed extremities. Each is surrounded 

 vvith a white, woolly secretion, which also extends partly over the 

 insect and thus renders its segmentation more apparent." The 

 females become full grown in early spring and the young appear 

 during the month of June. 



This insect occurs upon the elms in Marietta and according to 

 Burgess in Columbus is not known to occur in any other portions of 

 the state. According to Dr. Felt it is present in the following parts 

 of the Union: Vermont, Massachusetts, District of Columbia, Michi- 

 gan, Nevada, Colorado and New York. 



In June, 1906, the writer made a careful study of the condition 

 of the city of Marietta. The insect was found to occur in various 

 parts of the -city, the vicinity of the chair factory being seemingly 

 the center of infestation. It is not known definitely when it was 

 first introduced, nor is there any plausible theory as to how the in- 

 troduction was made. The trees were hot in a serious condition, 



