306 THE MONTHLY BULLETIN. 



LIME AND SULPHUR. 



Even l)etter than snlphur alone is dehydrated lime and flowers of 

 .sulphur mixed in equal parts and blown n|)on the trees with a power 

 machine, as is shown in P^ig'. 304. In the citrus orchards this is a very 

 important method of controlling the citrus red spider {Tetranychus 

 iiiytUasiAdis) and the six-spotted or yellow mite {Tetranychus himacu- 

 latus). 



LIME, SULPHUR AND SAL BORDEAUX. 



This mixture is prepared as fellows: 



Dehydrated lime (finely powdered slaked liui') 40 pounds 



Flowers of sulphur 5 pounds 



8al Boi'deaux (a mixture of bluestone. charooal and 



uaphthol) •"» pounds 



^lix these ingredients thoroughly and apply with a power blower. 

 This is one of the most efficient preparations now being used in con- 

 trolling the almond red spider {Bryubia prat ens is). 



PYRETHRUM. 



This is commonly known as Persian or Dalmatian insect powder, or 

 Buhach, and comes as a finely ground yellow powder with a pleasant, 

 rather pungent odor. It is a contact poi.son and most larv.i? and soft- 

 !)Gdied insects are thrown into convulsions when they come under its 

 influence. Unfortunately it is not only expensive but quickly loses its 

 effectiveness when exposed to the air. Its practical range is therefore 

 limited, and it is chiefly used on house plants, in the conservatory and 

 in the garden. It is entirely harmless to vegetation of all kinds and 

 does not spot or mark even the most delicate flowers when used dry. 

 It acts a little more promptly and effectively if applied to the insects 

 while they are moist, or at least damp. If the dusty appearance is 

 objectionable, a decoction may be made by steeping- one ounce in one 

 quart of boiling water, and then adding two or three quarts of cold 

 water. Into this material potted plants may be dipped, or it may be 

 applied with an atomizer. Against plant lice on house plants this 

 makes a very clean and effective application. 



HELLEBORE. 



Powdered white hellebore has been used for many years as a specific 

 remedy against "currant worms," "rose slugs" and other saw-fly larva?, 

 and is very effective, either dusted on as a powder, or in the form of a 

 decoction. In the field it is now quite generally replaced by arsenate 

 of lead or even Paris green, but in the garden it still holds its own. 

 When applied, it may be used pure, or it may be mixed with two or 

 three times its own weight of dust, cheap flour, lime, or almost any 

 other light, finely powdered material. When used as a spray, steep 

 one ounce in one quart of boiling water and add another quart of cold 

 water when ready to apply. 



