128 Report of State Board of Horticulture. 



petals were mostly off by May 10, the first eggs were not found until about 

 three weeks later. 



At Corvallis egg laying is delayed until a much later date. April 10, 11 

 and 12, 1898, moths were placed in breeding cages with fresh blossoms 

 for the purpose of obtaining eggs. None were obtained, however, and 

 neither eggs nor larvae were seen upon fruit out of doors until July 1, 

 when a single recently hatched larvae was foimd just beneath the skin of 

 a Waxen apple. July 4 three more were found, and on July 7, 97 of the 

 475 apples on the tree were found to contain young larvae. Allowing a 

 maximum of ten days for the egg stage brings the date at which the very 

 first eggs were deposited at June 21, while egg laying evidently did not 

 become general imtil about June 28. As shown above, the petals had fallen 

 by April 28, about two months before, in 1899, however, moths were placed 

 in breeding cages with fresh blossoms on April 21, 22, 25, 29, May 4, 5, 8, 9; 

 and on May 11 ten eggs were deposited. At this time the petals had been 

 off the trees scai'cely more than two weeks. However, no eggs or larvae 

 were obtained on fruit on the trees until June 28 when numerous eggs and 

 very young larvae were found on Ben Davis apples. In 1900 the blossoms 

 were mostly off by May 1. The first egg was seen June 11, another June 14 

 and the first larvae June 26. It appears from the above observations that 

 while the blossoms fell at various dates from April 28 to May 10, egg laying 

 rarely begins before the middle of June and is not general, much if any 

 before June 25. This does not hold true for the dryer and warmer parts 

 of the state, nor is it necessarily true for the entire "Willamette valley. 

 In southern Oregon and parts of eastern Oregon egg laying certainly begins 

 in May, and reports from various parts of the Willamette valley indicate 

 that the date at which the first larvae begin to work in fruit at Corvallis 

 is unusually late even for this section. 



EFFECT OF EVENIXG TEMPERATURE ON HABITS. 



I have been somewhat at a loss for a satisfactory explanation of this 

 variation from the normal habits of the insect. Knowing that the moths 

 are most active just as dusk, I have attempted to account for it on the 

 ground that our evenings are unusually cool throughout May and the 

 greater part of June. Corvallis lies directly opposite a gap in the Coast 

 range of mountains, which may account for the fact that it is daily blessed 

 with a cool sea breeze which rapidly lowers the temperature after three 

 or four o'clock in the afternoon. It is possible that this low temperature 

 may account for the delayed oviposition. To bring out this point more 

 clearly I have compiled the following table showing the daily temperature 

 at 8 p. m. from May 1 to October 1, practically the entire period during 

 which moths are on the wing here, for the years 1898, 1899, 1900 and 1901. 

 The record for May and September, 1898, was not available. 



Records of this character for only four years, and for one locality only, 

 do not prove anything. They may, however, be suggestive. In this in- 

 stance, if they show anything, it is that the moths do not deposit eggs 

 when the evening temperature falls much, if any, below sixty degrees, and 



