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JOmNAL OF ECONOMIC ENTOMOLOGY 

 LIME-SULPHUR WASH (30° B.) 1-30, DETAIL TABLE— Continued 



[Vol. 5 



and covered by the spray (which is impossible practically) the largest 

 percent mortality according to these results would be about 1-4 per- 

 cent. In view of the fact that a foliage spray must be used when spray- 

 ing for codling moth eggs, a one-to-30 dilution of a clear lime-sulphur 

 solution is about as "strong" as would ordinarily be used. This pre- 

 liminary experiment demonstrates to our satisfaction the ineffective- 

 ness of lime-sulphur as a codling moth ovicide. 



Notes on Development. In this lot, of twentj^-one white eggs only 

 two showed' the red ring before the appearance of the black spot. 

 Almost all eggs with a red ring when collected showed the black spot 

 before hatching. 



All the white eggs hatched. Of the sixty-three eggs with whole 

 or fractional red rings when collected, eight, about 13 percent, failed 

 to hatch. Of fifteen eggs showing the' black spots when collected, 

 six, 66 2-3 percent, failed to hatch. These records seem to indicate 

 that the eggs are killed later on in their development — at a period when 

 the embryo requires the most oxygen. Of the fifteen dead eggs the 

 fully developed embryo, recorded as "larva," was visible through the 

 chorion in eight. The embryo may have been as fully developed in 

 the other eggs but on account of the residue of the spray or the opacity 

 of the chorion could not be seen. 



Lime-sulphur Wash (30° B.) 1-30 and Lead Arsenate 4-100. Would 

 the addition of the usual strength (4 pounds in 100 gallons) of lead 

 arsenate be effective in preventing the eggs from hatching? To ob- 

 tain data on this question a third lot of twenty-three eggs were treated. 



