30 



ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



Rex solution, whitewash, K-L mixture, kerosene-whitewash, and 

 caustic soda. The number of eggs per tree was variable, but there 

 Avere not less than 400 eggs on each tree, and the maximum number 

 on one tree Avas 4,800. The total number of eggs by actual count 

 in the experiment was 223,920, of which 158,885 were firm, while the 

 rest were more or less shrunken. The trees were planted in boxes 

 of convenient size, and during the treatment were isolated to prevent 

 the applications from reaching other stocks. Each tree was exam- 

 ined daih', and as each egg hatched the aphis Avas killed and a record 

 was made of the daily hatching of the eggs. 



The results of the last two tests, which are representative, are as 

 follows : 



Fourth experiment : Less than 1 per cent of the eggs hatched on 

 trees sprayed Avith the sulphur Avash, crude oil, kerosene-AvhiteAvash, 

 and Rex solution. The percentages of eggs that hatched on the 

 trees receiving other sprays are as folloAvs : 



Per cent. 



( "austic soda 7. 3 



Kil-o-Scale 26. 



Checks 22.4 



Fifth experiment : No eggs hatched on the trees that received 

 applications of kerosene-AvhiteAvash and Avhitewash. On the trees 

 treated Avith the other sprays the folloAving percentages of eggs 

 hatched : 



Per cent. 



Snlplinr \A'ashos :>. n 



Scalecide 40 



Kerosene 1. "> 



Kerosene enmlsion H 



Whale-oil soaj) !) 



Per cent. 



Caustic soda 5 



Kil-o-Scale 4 



Crude oil 10 



Rex solution 1 



Checks 31.4 



Mr. Titus mentioned the fact that aphis eggs are often deposited 

 in such a manner on the twigs that they oA'erlap, and this being the 

 case it Avould be diihcult, and in some cases impossible, to coA'er all 

 the eggs AA'ith the spray material. In making an accurate statement 

 as to the ])ercentage of eggs destroyed by spraying, this i)oint and 

 parasitism sliouhl be considered. 



Mv. Ilodgkiss replied that the small size of the trees enabled a most 

 thorough ai)plication to be made in each iuid every case. The pur- 

 pose of the experiment being entirely to test the advisability of si)ray- 

 ing nursery stock, the question raised by Mr. Titus Avould in no Avay 

 affect the results obtained. Replying to a question on the value of 



