18 



and then tliey began slowl}- to increase in numbers again. As the 

 first eggs of this year were fonncl Jnne 19, this makes the time 

 between broods about 54 days. On August 20 it was difficult again 

 to find many unliatched eggs. 



SECOND BROOD OF LARV^. 



The earliest that we have taken mature larvae of this brood at Fort 

 Collins is August 3; at Canon City, August 1 ; at Rockyford, August 6, 

 and at Grand Junction, Jul}" 23, as determined by the dates at which 

 we have first obtained larvse that did not pui3ate till spring. (See 

 Table I.) Immediatel}^ following these dates the number of such 

 larvse rapidly increases until none are found except those which 

 remain in the larval state till spring. These last dates, in all our 

 observations, have been taken to mark the close of the appearance 

 of the first larval brood. The dates we have are, for Grand Junction, 

 August 13; for Rockj^ford, August 20; for Canon City, August 21, 

 and for Fort Collins, August 30. (See Table lY.) 



According to our observations this brood passes the winter entirely 

 as larvae, and begin active pupation at about the time the apple trees 

 begin to bloom. 



The pupa stage of this orood usuallj^ lasts much longer than that 

 of the summer brood. We have often had pup?e remain 30 or 40 days 

 before the moths emerged, and a considerable longer period has not 

 been very unusual. The longest spring pupal stage that we have 

 recorded is 68 days, March 7 to May 14, at Grand Junction. 



THE NUMBER OF BROODS. 



While the above data may be weak at some points, I believe it is 

 fairly safe to announce that the codling moth is definitely two-brooded 

 throughout Colorado, with no adequate reasons for postulating a par- 

 tial brood to account for the belated larvae that have fallen behind 

 the majority in the race. Let us see if the data we have presented 

 bear out the conclusions. 



According to our records the entire life historj^ of the summer brood 

 is divided into periods about as follows: From egg to larva, 7 days; 

 from larva to cocoon stage, 19 days; cocoon stage to emergence of 

 moth, 18 days; emerging of moth to middle of egg-laying stage, 5 days 

 (estimated) — a total of 49 days, or just 7 weeks. 



The first larvae matured in the apples last year at Fort Collins July 

 3, and we began taking larvae that lived over winter August 12 — just 

 40 days after. At Canon City Dr. Peare took the first larva June 15, 

 and the first larva that did not pupate was taken 47 days later — August- 

 1. Mr. Griffin, at Rockyford, took the first larva of the summer brood 

 June 15, and the first that lived over winter without clianging, 52 days 

 afterwards, August 6. Mr. Smith, at. Grand Junction, took the first 

 mature larva last year June 10, and the first to live over winter with- 

 out pupating, 43 days afterwards, Jul}' 23. As the time in each of 



