292 



Australia than that it came from any other country. I am able to add 

 before this number goes to press, that on January 5 Mr. Koebele wrote 

 from Kandy, Ceylon, that he had been unable to find this scale in Ceylon. 



POSSIBLE FUTURE SPKEAD. 



It may prove to be a significant fact that, although nursery stock 

 aflected by this scale has for six or seven years back been sent to all the 

 fruit-growing regions of the Eastern States, according to our present 

 information the scale has established itself only in regions contained 

 within the so-called austral life- zone. Mapping the points of estab- 

 lishment it is very interesting to see how accurately this distribution 

 has been followed. Professor Smith last summer called attention to 

 the fact that the spread of the insect in is^ew Jersey seemed to be limited 

 on the north by the so-called "red shale" line, extending, approxi- 

 mately, from Perth Amboy on the east to Trenton on the west. The sig- 

 nificance of this fact is shown when we remember that the transition 

 region enters northwestern New Jersey. The more northern occurrence 

 of the scale in Columbia County, X. Y., is similarly significant, since the 

 upper austral zone extends nj) the Hudson River. The occurrences at 

 Lewisburg and Bristol, and Atglen, Pa., are all within the extension 

 of the ujjper austral into the southeastern one-fifth of Pennsylvania. 

 The three Idaho occurrences are all in the narrow upper Souoran or 

 upper austral band along the Snake Kiver, with the exception of the 

 one at Lewiston, which is the only locality in the panhandle of 

 Idaho where the Sonoran dips in from the west. Should future obser- 

 vations support the apparent significance of the occurrences so far 

 known, the scale will not establish itself to any serious extent in tran- 

 sition regions. This fact will relieve New England fruit growers north 

 of southern Connecticut; those inhabiting the greater portion of Penn- 

 sylvania, exce])t in the southeastern one-fifth and a western strip; those 

 in New York, except for the strip up the Hudson River and the loop 

 which comes in from the northwest and includes the counties border- 

 ing Lake Ontario on the south, as well as those inhabiting the northern 

 portion of the lower peninsula of Michigan and all of northern Wis- 

 consin, from any fear of this insect. Such a condition of attairs would 

 seem almost too good to be true, but the possibility of its truth is sug- 

 gested by what we know up to the present time. Against its proba- 

 bility may be urged the fact that, in general, scale insects belong to tl e 

 groui) of potential cosmopolites and that they are seldom restricted by 

 geographical limitations which hold with other insects. 



REMEDIES. 



If the horticulturist who possesses an orchard infested by the San 

 Jose scale wishes to apply as summer washes either the summer resin 

 wash or ordinary dilute kerosene-soap emulsion as formulated in 

 Farmers' Bulletin 19 of this Department, he will be able to keep the 



