ENTOMOLOGY 283 



almost completely cleared of the pest, and additional treatments 

 have not been found necessary thus far. 



The Golden Oak Scale. The scale is easily determined on 

 account of a yellowish-green golden color and because it causes a 

 slight abnormal growth upon the twig, thus presenting the appear- 

 ance of being partially imbedded in the bark. Although alive, the 

 trees infested were not healthy, the bark being very rough and un- 

 even and seemingly only partially able to fulfill its duties. Kero- 

 sene emulsion is an effective remedy when applied during the 

 hatching period. 



Pit-Making Oak Scale. This scale is circular, usually green- 

 ish-yellow in color, and has a glassy appearance. It forms a pit or 

 depression in the bark where it is situated, and it is about 2 mm. in 

 diameter. This species has been sent to the Station several times 

 on English oak, Quercus robur, though it is know T n to attack other 

 oaks. Kerosene emulsion and whale oil soap have been used as a 

 spray with good results in destroying this insect. 



Oak Gall Scale. A globular gall-like scale found on oak twigs. 

 It is grey, about as high as long, and slightly 'broader than its 

 length, which is about one-fourth of an inch. There is a longi- 

 tudinal dorsal furrow or constriction. 



Euonymus Scale. The euonymus scale resembles the scurfy 

 scale, but the females are somewhat smaller and darker in color. It 

 passes the winter in the egg stage, and the different species of 

 Euonymus and the orange are attacked. (Fifth Kept. Entomologist 

 Conn. Agr. Exp. Sta.) 



The Pine Bark Aphid. Though not a scale, this insect may 

 logically be considered here, as its appearance is much the same as 

 that of some of the scales and the control methods are similar. The 

 adults may be seen as collected in thick, white, floculent masses 

 upon the base of the pines. The pest is subject to the action of 

 contact sprays, according to Dr. E. B. Southwick, Entomologist of 

 the New York parks, the stiff sprays being effectual. 



The Elm Leaf-Louse. On some bright day in October the 

 air will seem filled with myriads of tiny, woolly, blue-black insects, 

 slowly flying to the elms and alders. Gradually they alight and 

 start an upward procession, crawling up the trunk. By evening 

 the trunk of the tree will be covered with insects. Another day and 

 none will be seen, but the ground at the base is covered with their 

 spent bodies. This host of plant lice fly to the elms to give birth 

 to tiny yellowish young, which are the only sexual generation of 

 the year. The yellow lice crawl into cracks of the bark whore each 

 lays a single egg. It is in this egg stage that the winter is passed. 



When the trees leaf out in the spring the eggs hatch. The 

 young plant lice crawl out on the branches and each selects a leaf. 

 As a result of the insect's feeding the leaf becomes swollen and 

 curled. Within this leaf retreat the louse gives birth to many 

 young, so that during early summer curled leaves will contain sev- 

 eral dozen individuals of various ages. At this stage a disagreeable 

 amount f sti^y honey dew is secreted, which falls to the sidewalks 



