88 BULLETIN 932, U. S. DEPARTMENT OF AGRICULTURE. 



wormy, it is believed that had there been a large influx of moths from 

 the hundreds of acres of surrounding orchards in which there was no 

 fruit, it would have been practically impossible to have saved the 

 crop with the normal spraying schedule. 



In order to determine how far the adults can actually fly, it was 

 thought desirable to make some moth-flight tests. Accordingly, 

 trials were made on the mornings of June 11, 17, 24, July 27, 29, and 

 August 3, 1915. These tests were usually made earty in the morning 

 and. in so far as possible, when the atmosphere was quiet and the tem- 

 perature moderately low in order that the moths would fly at a slow 

 speed. When the wind is moderate to strong or the temperature 

 high, the moths are very rapid in their flight, so that it is impossible 

 to follow them. 



The moths were released one at a time from a central point, and 

 Mr. Van Leeuwen and the senior author followed their course on foot. 

 In all, several hundred moths were released and out of this number it 

 was possible to secure data on a few. In many instances the moths 

 ascended high into the air and were lost from view, in other instances 

 they dropped into bushes, while in some cases their flight was either 

 too erratic or swift to follow. The flight of the male moths was gen- 

 erally much more irregular and speedy than that of the other sex. 



In determining the distance covered, measurements were made 

 from the starting point to the place where the moths dropped or were 

 lost from view. It should be noted, however, that the actual distance 

 between the starting and finishing points, as measured by pacing, 

 was usually only a small part of the distance the moths flew, since 

 they seldom went in a straight line and it was impossible to take 

 into account the numerous deviations from a direct course. Never- 

 theless, an attempt was made to estimate the number of feet actually 

 traveled during the flight whenever the moths proceeded in a new 

 direction for a considerable distance. This was done by counting 

 the steps of the observers and allowing a certain distance per step. 

 In this connection it should be borne in mind that the estimated dis- 

 tances, although approximate, are conservative. 



In Table LXIY the flight records of 35 moths are given. Three 

 of these covered a distance of over a thousand feet in one flight, 

 measuring from the point of release to the place where the moths 

 disappeared from view or dropped to the ground. The maximum 

 air-line distance of 1,344 feet was made by a male moth. One female 

 moth that flew, in ti\ minutes, a distance of 1,035 feet measured in a 

 straight line, traveled an estimated distance of 3,000 feet and was 

 still flying when it disappeared from sight. Another female moth, 

 after flying continuously for 74 minutes, was lost from view. 



It would seem from the foregoing that the codling moth is capable 

 of making a fairly long and sustained flight, but it does not neces- 



