EXPERIMENTS IN ZOOLOGICAL DEPARTMENT. xll 



Applied to Codling Moth (Carpocapsa pomonella, Linn.). 



The effect of this application upon the codling moth larv« was also noted. 

 The application was rather late. It should always be made as soon as, or be- 

 fore the apples are as large as peas, else some of the larvae will have passed 

 into the fruit out of reach of the poison. One hundred apples from each of 

 two Go'den Russet trees were examined early in October. From the tree poi- 

 soned sixteen apples were not wormy ; of the 100 from the tree not treated 

 only two were sound. Sixty apples each from four Talman Sweet trees were 

 examined. From the two trees poisoned fourteen and twenty-five apples re- 

 spectively were found sound ; from the two not poisoned six and nine. A Si- 

 berian Crab apple tree was treated May 31st. The apples were about the size 

 of large peas. The application was very thorough. Many apples were exam- 

 ined in September and not one was wormy. Another Crab apple tree, not 

 treated, not three rods distant, had hardly a sound apple. The same was 

 true of several other trees close by. Two conclusions seem evident. For cod- 

 ling moth the Paris green mixture should be applied early, the mixture should 

 be very dilute and the application very thorough. It is worthy of remark that 

 four or five cents per tree is all that this costs, counting the labor, while its 

 efficiency when rightly performed is wonderful. 



Paris green was used for the cabbage maggot. Strength one ft), to forty gal- 

 lons. It neither injured the plants nor the insects. 



CALIFORNIA PYRETHRUM OR BUHACH. 



This powder, one year old, and not as strong as is fresh powder, was used with 

 varying success. It was tried very thoroughly both as dust and in water for 

 cherry plant lice, but to no effect. To the cherry slug it was very destructive 

 as a powder, but did no good in water. Placed about radish plants every few 

 hours it did no good in fighting the radish maggots. 



TOBACCO AS AN INSECTICIDE. 



This was used both as a decoction and as a powder, and it was very thor- 

 oughly applied. The plants on whicli the decoction was used were nearly all 

 destroyed by the maggots. The same was true of those treated with the 

 powder. The tobacco does no harm to plants. 



Tobacco powder applied to Cabbage Flea Beetle {Phyllotreta striolata, Fab.). 



This was applied when the dew was on the plants, and while it did no in 

 jury to the plants, it seemed very largely to drive off the beetles. 



UNLEACHED ASHES. 



These were used against the anthomyia with no success. Sprinkled upon 

 the foliage it injured the plants seriously. 



GAS LIME. 



This was also iised against the anthomyia. It killed the plants but did no 

 harm to the insects. It was used as a powder and in water. The latter was 

 not quite so injurious to the plants. 



The above experiments were entirely in charge of Mr. C. P. Gillette, whosfr 

 faithfulness and caution leaves little to be desired. 



V A. J. COOK. 



