4 



combating scale insects which suck the juices of plants; instead, a 

 corrosive or oil}' contact insecticide is necessarily used. 



SUMMER TREATMENT. 



All scale insects are protected by waxy coverings of different kinds, 

 except in the j^oung larval stage, in which stage they are most easily 

 destroj^ed by insecticides. The most effective treatment which is least 

 injurious to the plant is the use of kerosene emulsion spra3"ed with 

 some force on all parts of an infested plant at the time of the hatch- 

 ing of the young, using special care to cover thoroughly both sides of 

 all leaves and twigs. The time of first hatching of the young varies 

 with the seasons and latitudes, and extends from the first of Ma}^ to 

 the middle of June in different localities. Where no frost occurs the 

 dormant season is verj^ short. Repeated thorough sprayings of in- 

 fested plants at intervals of two weeks between the above dates siiould 

 effectively control this scale. Emulsion sti'onger than 15 per cent of 

 oil should not be used on plants during the summer, else the foliage 

 might suffer. 



-WINTER TREATMENT. 



During the winter season plants are dormant and are able to withstand 

 stronger insecticides without injury. The deciduous species of Euony- 

 nms should be treated after the falling of the loaves, or during winter, 

 with a 25 per cent kerosene emulsion, or a solution of whale-oil soap 

 at the rate of 1 pound to a gallon of water. The evergreen species 

 and varieties can withstand 20 per cent kerosene emulsion during the 

 dormant season. Care should be used to prevent the collection of the 

 oily emulsion at the base of a treated plant, else injury may result. 



Directions for the preparation of kerosene emulsion and the propor- 

 tions of the ingredients are given below: 



KEROSENE EMILSION. 



Stock .solution (()6 per i-ent oil). 



Kerosene (coal-oil, lamp-oil) gallons. . 2 



Whale-oil or laiuidry soap (or 1 (juart soft soap) pound. . i 



Water gallon . . 1 



Dissolve the .soap in boiling water, tlunt 'remove from the Jire^ add the 

 kerosene immedlatel}', and thoroughly agitate the mixture until a cream}- 

 solution is obtained. This can be done by pouring the mixture into 

 the tank of a spray-pump and pumping the liquid through the nozzle 

 back into the. tank. This is a stock solution which nuist be diluted 

 before using. In order to make a 20 per cent enmlsion, add to each 

 gallon of the stock solution about 2;^ gallons of water and agitate thor- 

 oughly before using. For a 25 per cinit solution add to each gallon of 

 the stock solution If gallons of water and agitate thoroughly. This 



[Cir. 114] 



