188 



One of the main objects of this circular, therefore, is to emphasise the 

 importance and value of honest efforts to control this insect for the great 

 majority of districts where it has established itself, rather than efforts at 

 extermination, which will prove successful rarely, at best, and wall always 

 be accompanied with great immediate loss. The other principal object is to 

 designate, briefly the means of controlling this scale insect which experience 

 has shown to be of practical value. 



The Lime and tiuJithur Wash. 



This is the invariable remed.v for the San .Jose Scale in California and 

 much of the Pacitic I'oast. and it is. under the conditions of climate obtaining 

 in that region, undoubtedly very effective. Early experience with this wash 

 in the Kast threw doubt on its efficiency as an insecticide under the climatic 

 conditions prevailing throughout the ea.stern half of the United States. 

 Some later experiments, however, have shown that wherever the weather 

 conditions happen to be very favourable, duplicating, in a measure, the con- 

 ditions on the Pacific Coast, this wash is effective in the East also. Unfor- 

 tunately, the weather conditions cannot be relied on, and, therefore, its use 

 in the East is uot recommended. But if a considerable period (10 days or 

 two weeks, at least) of dry weather could be assured after the treatment, it 

 would probably give very satisfaetor.v results when properly made and 

 applied. It is a winter application and is applied in January or February, 

 or at any time prior to spring growth. 



This wash is applied nearly ever.v year, or as often as the San Jose 

 Scale develops in any considerable numbers. It has the advantage of leaving 

 a limy coating on the trees, which acts as a deterrent to the young scale-lice, 

 and where it is not washed by rains retains its value as an insecticide coating 

 for .some time, remaining in evidence on the trees for several months. — 

 Circular 'No. 2, U. S. Dcjiartmeiit of Afiricitlturr, Dirision of Entomologii. 



Orchards very hndlii infested vith Sun Jose Scale should he spraijcd 

 ticice, once in fall or early icintcr and again in si>rinp before the liuds open. 

 It is well nigh impossible to cover every portion of the tree at one spraying — 

 though that should by all means be the aim — hence, where orchards are 

 badl.v infested, it is advisable to spray twice each year until the scale is well 

 in control. Thorough application of lime-sulphur wash, covering the trees 

 from top to bottom, is necessary if good results are to be exiiocted. Too often 

 orchardists spray their orchards without proper regard to thoroughness, and 

 the result is that they fail to get good results and theu think the wash is 

 responsible. Lime-sulphur wash does uot spread easily like oil emulsions, 

 and great care in spraying is necessary if good results are to be obtained. 

 On windy days it is almost impossible to cover a tree on all sides with any 

 mixture and on such days the lime-sulphur wash has its advantage, because 

 it is easy to see at a glance what portion of the trees has been covered. 

 The white coloured wash will show for itself. Frequently it becomes neces- 

 sary to spray one side of the trees one day and wait until the wind blows 

 from another direction before finishing the spraying. 



When spraying orchards to control the San Jose Scale, it is imperative 

 that all trees be sprayed. Not simply the trees that show infestation, but 



