316 CALIFORNIA VEGETABLES 



the extract of which is carried down by water to the discomfiture 

 of the pest, is often effective and profitable. 



Another group of biting pests though not strictly insects are 

 slugs and snails. They can be poisoned by the use of poisoned leaves 

 laid on the ground, or they can be trapped either with leaves or 

 pieces of board or little piles of wheat bran. Early in the morning 

 the slugs will be found in large numbers under the leaves or boards, 

 or collected in the bran, and can easily be gathered up for breakfast 

 in the poultry yard. Mother hens in portable coops with the young 

 chicks running among the plants, are a very good solution of the 

 slug question on a small scale. Myriads of slugs in the garden are 

 often due to excessive surface irrigation. If the surface is finely 

 worked up and allowed to dry it is very discouraging to slugs and 

 is otherwise promotive of plant growth. 



Remedies for Sucking Insects. These are pests both large and 

 small which bring distress to plants without visibly consuming their 

 substance, as has already been described. They are not affected by 

 poison on the surface. They must be killed by applications which 

 destroy by contact with the exterior of the insects. The universally 

 approved remedy for this large class of pests is kerosene emulsion. 

 If properly made and diluted, it is harmless to the plant and deadly 

 to the insect. The formula which is most easily prepared and most 

 available for garden work, is that devised by Prof. A. J. Cook as 

 follows : 



Common laundry soap -)4 pounds. 



Kerosene .3 pints. 



Water 4 l / 2 gallons. 



Cut up and dissolve the soap in six quarts of boiling water in a 

 five-gallon oil can. Remove from the fire and add the kerosene, stir- 

 ring vigorously for ten minutes. This should make an emulsion from 

 which the oil will not separate when cool. It can be diluted with 

 water enough to fill the five-gallon can, and is then ready for appli- 

 cation with a garden syringe or spray-pump, and it will kill all in- 

 sects which are covered with a film of it. A fine rose sprinkler can 

 be used, but it is wasteful and the application does not penetrate as 

 well as from a spray-nozzle. 



The kerosene emulsion will of course kill the insects for which 

 poison has been prescribed and is available whenever the use of 

 poison is thought to be undesirable. 



