24 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [BuU. 



composed of copper sulphate and lime, and the lime being in 

 excess prevents any injury occurring from the Paris green. 



Hellebore acts as an internal poison and also as an external 

 irritant, and is especially effective when used against the larvae 

 of sawflies, such as the imported currant worm. Hellebore 

 may be used as a dry powder, or mixed with water in the ratio 

 of one ounce to two gallons. 



Sucking insects must be killed by other methods, as they 

 insert their tiny beaks into the tissues and suck out the sap, 

 and would not therefore obtain poison which was applied to 

 the surface of the leaves. 



It is necessary to destroy them by some application which on 

 coming in direct contact with their bodies will kill, either by 

 irritating or corroding them, or by stopping up their breathing 

 pores and suffocating them. Various oil emulsions have the 

 latter effect, and soap mixtures act in both ways, especially if 

 they contain free potash. Kerosene emulsion may be made as 



follows : 



Kerosene 2 gals. 



Common soap Yz lb. 



Water i gal. 



Dissolve the soap in hot water, add the kerosene, and churn 

 together until a white, creamy mass is formed which thickens 

 on cooling. Dilute with nine times the amount of water before 

 using. 



Common laundry soap dissolved in the ratio of one pound 

 in eight gallons of water is an excellent contact insecticide, and 

 is effective against most plant lice. 



For several years the lime and sulphur mixture has been 

 the chief remedy for trees infested by the San Jose scale insect, 

 Aspidiotus perniciosus Comst. 



Lime and Sulphur Mixture 



Fresh finishing lime 20 lbs. 



Fine sulphur flour 14 lbs. 



Water 40 gals. 



Boil one hour, and apply while fresh to dormant trees. 



The so-called " soluble " or miscible oils which are now being 

 recommended instead of the lime -and sulphur mixture, are really 

 emulsions. 



