New York Agricultural E)xperiment Station. 451 



seue emulsion, diluted with from four to six parts of water, could 

 be depended upon to kill the hibernating scales when applied to 

 the infested trees in the form of a spray. When the spray is to 

 be directed against the newly hatched lice, the emulsion should 

 not be diluted with more than nine parts of water. 



The Oak Scale. 

 Asterodiaspis quercicola Bouch6. 



There are but few references to this insect in the writings of 

 American entomologists. In his report for 1880, p. 330, Prof. 

 J. H. Comstock, who was then Entomologist of the United States 

 Department of Agriculture, published a description of the male 

 and female, the former being taken from Signoret. Another ref- 

 erence is in Insect Life, Vol. II, p. 41, in which Ur. L. O. Howard 

 states that this scale is found almost solely upon American oaks 

 in a grove in the Department grounds, previously referred to by 

 Professor Comstock in his report for 1880. In Insect Life, Vol. 

 VII, p. 120, Mr. C. L. Marlatt gives the result of experiments 

 against this insect. He found that the newly hatched young 

 could be killed by spraying the infested trees with kerosene emul- 

 sion, one part to thirteen parts of water. In the same volume, 

 page 428, a brief reference is made to a note by Mr. K. Newstead 

 in the Entomologist's Monthly Magazine for April, 1895, in which 

 he states that, although birds are not usually supposed to feed on 

 scale insects, he had found that the blue tit and longtailed tit 

 feed on this and certain other species. 



It is probable that, except in isolated cases, the species has 

 never been a serious pest in this country. 



As its name implies, this scale attacks the oak. iSome idea of 

 its general appearance can be had by referring to Plate XIX, 

 fig. 6. This figure is from a photograph of an infested twig, 

 natural size. The female scales are nearly circular and somewhat 

 conical. They are dark or yellowish green in color. When one of 

 the mature scales is removed, it will be found to have made a pit- 

 like depression in the bark. The mature female scales will meas- 

 ure from 1 mm. to nearly 2 mm. in diameter. According ^o Sig- 



