272 STATE HORTICULTURAL. SOCIETY. 



few reports that the kerosene emulsion is powerless to kill lettuce lice in 

 forcing houses in winter. If, after observing the suggestions given above, 

 this ill success still occurs, we would urge that the pyrethro-kerosene 

 emulsion be used. We are quite sure it will prove fatal. Indeed, pyre- 

 thrum extract or pyrethrum in water, is alone generally fatal to these 

 lice. If the pyrethro-kerosene emulsion were applied hot, and it would be 

 no more difficult, say at a temperature of 130° F., we would have yet 

 another element of destruction. So I am sure our lettuce, growers need 

 not despair of success because of the lettuce plant louse. 



KEROSENE EMULSION AND THE PEAR AND CHERRY SLUG. 



We find that the kerosene emulsion is quick death to the cherry slug, 

 Eriocampa (Selandria) cerasi. In case a tree is suffering both from slugs 

 and plant lice, then surely we should use kerosene emulsion, and kill two 

 birds with one stone. 



KEROSENE EMULSION AND THE PEA WEEVIL. 



As is well known, the pea weevil, B ruckus pisi Linn., is a very common 

 and troublesome insect in all the northern states. The yellow eggs, often 

 as many as eighteen, are glued to the outside of the pod. On June 16, we 

 sprayed our pea vines with kerosene emulsion, marking several pods on 

 which were eggs, and noting the number and position of the eggs; June 25,. 

 an examination was made, of the four marked pods, and not a single larva 

 was found in the peas. An extended examination of the pods sprayed did 

 result in finding some larva? but by no means as many as were found in 

 pods or vines untreated. We think there is very little doubt that the 

 use of kerosene emulsion would reduce the injury from the pea and bean 

 weevils very materially. Whether the advantage would warrant the outlay 

 for any but those growing seed, I can not say. We also tried London 

 purple on the peas in the same way, but with no seeming advantage. 



STRENGTH OF KEROSENE EMULSION. 



A large number of experiments were made June 30, and repeated two 

 weeks later, to determine the maximum strength of kerosene emulsion,, 

 both soft soap (No. 1) and hard soap (No. 2) and of pyrethro-kero- 

 aene emulsion, which it would be safe to use on our cultivated plants. 

 The experiments were tried on cucumbers, squashes, peas, cabbage, rasp- 

 berry, rose, currant, grape, quince, peach, plum, apple, and cherry. As 

 fifteen experiments were tried on each plant, there were nearly four hun- 

 dred in all. We used one part of kerosene to 10, to 12-|, to 15, to 20, and to 

 25, of the soap solution. The plants were examined very soon after treat- 

 ment, and again some days later. Our conclusion is that a one fifteenth 

 hard-soap emulsion (No. 2) is safe on all plants. 



We can not say that of the soft soap emulsion (No. 1), though it has 

 been true in our experiments of previous years. In a few cases the plants 

 were injured. This was doubtless due to the quality of soap as already 

 explained. We like the soft soap emulsion and like the full quantity of 

 soap, but if upon trial plants are injured, the amount of soap may be 

 reduced one half. We found we could safely use the pyrethro-kerosene 

 emulsion on all plants with which we experimented at the strength of one 



