114 Agricultural Experiment Station, Ithaca, N. Y. 



beetles on the eggs and njmphs of tlie pear pjslla. Our corres- 

 pondent in Clinton, Mich., writes that he has "noticed the common 

 ladj-bug feeding on the nymphs of the pyslla." 



Birds have been seen picking the adult psjllas out of their winter 

 retreats in Niagara county ; so industrious were the birds that but 

 few pysllas were left on some trees. 



How to Coimbat Pear Psylla. 



The eggs. — Although the eggs laid early in the spring are freely 

 exposed on the bark to the action of insecticides, yet we were sur- 

 prised to find that many of them hatched after they had been dipped 

 in kerosene oil, turpentine, benzine, and several of the washes used 

 for killing scale insects. Mr. Marlatt reports that in July he killed 

 many of the eggs laid on the leaves, by spraying with a kerosene or 

 whale-oil soap emulsion diluted with from seven to nine parts of 

 water. However, as many of the eggs cannot be killed in this way 

 and as the insect can be combated much more effectively in another 

 stage, we do not consider it advisable to tight it in the egg-stage. 



The nymphs. — Our experiments in 1892, showed that the 

 nymphs in all stages were quickly killed by kerosene emulsion.* 

 Others who have tested it thoroughly report success. 



Usually most of the 'damage is done in this State by the first 

 brood of nymphs before June 15. It is therefore very important 

 that the insect should be checked early in the season. We now 

 advise using the emulsion diluted with about fifteen parts of 

 water, instead of with twenty-five, as it is more effective against 

 the nymphs, and it will also kill the adult insects. As the nymphs 

 begin to hatch just as the leaves are expanding, then is the time to 



* The formula is I pound hard or soft soap, 1 gallon water, 2 gallons, 

 kerosenf". 



First, thoroughly dissolve the soap in boiling water. While this solution 

 is still very hot add the kerosene; if the whole is then left over the &ve 

 for a few moments to raise the temperature of the kerosene slightly, it 

 will facilitate the emulsifying process. Remove from the fire and quickly 

 begin to agitate the whole mass through a syringe or force pump of some 

 kind; draw the liquid Into the pump and force it back into the dish. 

 Continue this opei'ation for five minutes or until the whole mass assumes 

 a creamy color and consistency which will adliere to the sides of the 

 vessel, and not glide off like oil. If desired for use immediately, it may 



