17 



If we combine the stages above given and call the two the cocoon 

 stage, we shall have a record as follows: One moth appeared in 12 

 days; 3 in 14 days; -1 in 15 daj^s; 1 in 16 days; 11 in 17 days; 13 in 18 

 dsijS', 18 in 19 days; 7 in 20 daj^s; 10 in 21 days; 12 in 22 days; 7 in 

 23 days; 8 in 21 days; 3 in 25 days, and 3 in 29 days. This makes 

 the shortest time in the cocoon stage 12 days and the longest time 29 

 days, and the average 20 days. 



Hatching records kei3t for me by Mr. H. II. Griffin, at Rocky ford, 

 and at Grand Junction by Silmon Smith, indicate that the duration of 

 the cocoon stage in those localities is ^practically the same as at Fort 

 Collins. Riley ^ gives the entire cocoon stage as 15 to 21 days, Wash- 

 burn- as three weeks, and Slingerland^ as two or three weeks. 

 Aldrich^ gives the time as a week or more, but greatly dependent upon 

 temperature. 



THE SECOND BROOD OP MOTHS. 



The time of appearance of the earliest of the second-brood moths is 

 easily determined by hatching them from the earliest wormy ajDples 

 of the summer. Rile}^ gave this date for the latitude of St. Louis, 

 Mo., as July 8; Le Baron gave it for northern Illinois as July 15; 

 Card, for Lincoln, ^N'ebr., as Ju,ly 2; Cockerell, for Mesilla Park, 

 N. Mex., as June 26, and Professor Cordley has written me that for 

 Corvallis, Oreg., he finds it to be about August 1. At Fort Collins 

 the earliest bred moth of this brood ai3peared July 13; at Canyon 

 City, Dr. Peare reports to me that he bred a moth July 15; at Rocky- 

 ford, Colo., Mr. Griffin obtained the first moth July 5, and at Grand 

 Junction, Mr. Smith obtained a moth on June 28. 



The following records <for the very latest moths appearing of this 

 brood (or some later brood, as the case ma}^ be) are of interest in this 

 connection. The latest moth to appear in breeding cages at Fort Col- 

 lins came out September 16; the latest at Canyon City, September 10; 

 at Rockyford, September 15, and at Grand Junction, September 12. 

 These are all belated individuals, and all appeared after the general 

 disappearance of the brood. (See Table IV, giving proportions of 

 larvse that live over winter from different dates. ) 



THE SECOND BROOD OF EGGS. 



I know of no definite published records upon the second brood of 

 eggs. At Fort Collins, this year, this brood seemed to begin its appear- 

 ance about July 24, and they were most abundant about August 12. 

 The two broods doubtless overlap, but at Fort Collins this year it was 

 almost impossible to find eggs at all from the 20th to the 23d of July, 



1 Fourth Mo. Rep., p. 22. 



2 Bill. 25, Or. Exp. Sta., p. 5. 

 "Bui. 142, Cornell Exp. Sta., p. 27. 

 ^ Bui. 21, Id. Exp. Sta,, p. 101. 



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