17 
By adding fifty-five days to August 27 (the average time in 1901 of 
the maxima for the second generation), we should expect the maximum 
of the third generation entering bands. At that date (October 19) no 
such maximum appears upon the various records. It was noted in 
1901 that none of the larvae which spun cocoons after September 1 
transformed, but all wintered as larvae. In 1900 the corresponding 
date was September 7. 
Mr. McPherson observed the period of the greatest number of eggs 
of the •first generation to be from May 10 to May 25. The writer 
observed the same period of the second generation to be from about 
July 13 to August 1. But when the time came for the Qgg period of 
the third generation very few eggs were seen. 
Observations were made daily in the orchards and the courses of 
these generations were watched as carefully as possible. On account 
of the variability of location of orchards and the overlapping of gener- 
ations, observation is very liable to lead to error and can not be taken 
as proof except in so far as corroborated by other evidence. 
It has been often noted that many }^oung larvae enter the apples in 
September. Whether these are the last of the second or the first of 
the third generation is a question which has puzzled the writer. .But 
few of these new entrance holes were observed at Boise last Septem- 
ber and October, and the writer is inclined to believe that the larvae 
were the last of the second generation. If there was ever a full third 
generation, or a partial one, it should have occurred in 1901 by reason 
of the earliness of the season. 
Professor Gillette's article on the generations of this insect has been 
carefully read. In general the writer's conclusions are the same, but 
the3 T are based on data of a very different kind. The writer can 
not agree with Professor Gillette when he says that it is impossible 
for a partial third generation to be produced. A study of the life 
zones will show that we should expect some differences between the 
life history of the insect in Colorado and the same in Idaho. 
The writer confesses that on many points there is a lack of data, 
and on this account does not wish to make the sweeping assertion 
that there are only two generations of the codling moth in southern 
Idaho. Whether or not there may be a partial third generation is 
still an open question and one which can be solved only b}^ careful and 
accurate work. This much, however, is reasonably certain: The third 
generation is of little or no importance, whereas in the past it has been 
regarded as a full brood. 
All future work will be based upon the assumption that there are 
two generations. It is hoped that next season's work will throw more 
light upon these doubtful points and fully establish the facts. 
With the knowledge that there is no fourth brood and no full third 
£7341— No. 35—02 2 
