186 



STATE BOARD OF AGRICULTURE. 



Most eggs and young larvae, June 12. 



Most larvae, June 15. 



Moat spun up in cocoons, July 12. 



SKCOND GENERATION. 



Most adults, July 27 (shown in cages from fresh cocoons). 

 Most eggs, August 6. (Spray at this time.) 

 Most larvae, August 11. (Young larvae shown in orchard.) 

 Most cocoons just spun up, September 2. 



I POSSIBLE THIRD GENERATION, FROM COMPUTATION, AND NOT FROM OBSERVATION. 



Most adults, September 23, (due at this time). 



Most eggs, October 1, (due at this time). 



Most larvae, October G (due at this time). 



In his work on the codling-moth, Mr. Simpson refers constantly to the bands 

 placed about the trunks of trees for the purpose of providing suitable places for 

 the larvae to pupate. By the \ise of these bands, he was able to get reliable 

 and indisputable data on the time of pupation at least. By daily counts he 

 readily determined the exact times when the larvae went in as well as when the 

 adults came out. We tried these bands made of burlap, but with very indifferent 

 success in 1903, over half of the larvae not caring to utilize them but preferring 



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I 





Fig. 2. — Codling-moths. From Slingerland. 



for the most part, to pupate under loose flakes of bark instead. For this reason, 

 we were obliged to substitute some other plans for keeping counts. The orchard 

 which we used was a large one, and one that contained trees of all ages, so 

 we determined to spend about the same amount of time and labor each day in 

 searching for the larvae which were just spinning up in cocoons, and for the 

 eggs and young larvae on or in the fruit. This plan would seem at first to be 

 very crude and to promise little in the way of accuracy, but when we consider 

 further that each count is double in character, and that cocoons are compared 

 each day with larvae, and that eggs are compared with young larvae, that the 

 emergence of the adults is checked by cage experiments, we will find that while 

 the method may be inferior to that of banding, it does readily give us useful 

 facts and with a fair degree of accuracy. Our bands failed because the flakes 

 of bark offered more desirable quarters. During 1904, we selected ten trees in 

 an old orchard which was not to be sprayed, and scraped off all flakes and scales, 

 thus driving most of the larvae under the bands. We also obtained more accurate 

 information relating to the time of the first appearance of the adults in the 

 spring. 



In order to collect evidence relative to a possible third brood, two trees, un- 

 sprayed except for the first spraying, in the College orchard, were carefully 

 gone over and all wormy fruit removed on September 18 and 19, just before the 

 adults of the third l)rood might be expected, if at ail; a glance at the schedule 



