226 NEW YORK STATE MUSEUM 



moistened, has been found very effective against cut worms. Some prefer 

 to sweeten it with cheap sugar or molasses, specially for grasshoppers. 

 The disadvantage of the mash is that it soon dries and then is of no 

 value. In experiments against cut worms in onion fields, Mr Sirrine 

 found that either dry bran and paris green in equal parts or 20 pounds 

 of middlings to i pound of poison was a very effective bait. 



Internal and contact insecticides combined. Hellebore and 

 tobacco may act either internally or kill by contact. One ounce ot 

 fresh white hellebore thoroughly mixed in 3 gallons of water is a 

 proportion recommended by Lodeman and Gould,^ while Dr Smith 

 gives I ounce to 2 quarts of water. It may be applied pure or 

 mixed with plaster or flour if desired. It is used largely against currant 

 worms, specially when the presence of nearly mature fruit prohibits the 

 application of paris green. 



A strong decoction of tobacco may be prepared by boihng stems and 

 other refuse till a deep brown extract is obtained. A few trials will 

 enable one to ascertain how much this can be diluted and still be effec- 

 tive. It may be used successfully as a contact insecticide against soft 

 bodied insects Hke plant lice, saw fly larvae and others, and it may ako 

 serve as a repellant or poison when applied to plants for the purpose of 

 protecting them from attacks by flea beetles, and many other insects. If 

 in the form of a fine dust, it is a very effective contact insecticide, and 

 may be used with great advantage on the surface or worked into the 

 ground around trees infested with root lice and other subterranean in- 

 sects. In greenhouses it is very valuable, when stems or leaves are laid 

 around, specially on the heatmg pipes, as its odor seems to be unfavor- 

 able to insect life. There is no easier method of keeping plant lice under 

 control in a conservatory than by fumigation with tobacco smoke. 



Contact insecticides. The most important of those commonly used 

 are kerosene emulsion,- whale oil soap solution and pyrethrum. 

 The standard kerosene emulsion is prepared as follows: 



Hard soap i pound 



Water i gallon 



Kerosene 2 gallons 



Dissolve the soap in boiling water and while still hot add the kerosene 

 and emulsify by passing it rai)idly through a force pump till it assumes 

 a creamy consistency and oil does not rise to the surface. Dilute with 9 

 to 15 parts of water. In limestone regions where hard water is the rule, 

 better results will probably be obtained by using the sour milk emul- 



a BulUtin 114, Cor >icU university agricultural experiment station. 



