23 



annually and probably no more. Mr. Gillette had found that the 

 first brood extends over about sixty-nine days — that is, the moths 

 from this brood have continued to emerge for that number of days at 

 Fort Collins. 



Doctor Fletcher called attention to the fact that the difference in 

 the time of hatching of eggs is very common in nature. Ten days' dif- 

 ference in the time of egg laj'ing might have considerable bearing on 

 the date of maturity of the progeny. Larvse hatching early might 

 mature the same season, while later individuals would go over the 

 winter. He referred to the fact that Mr. C. B. Simpson had proved 

 that the larvae of the codling moth were able to develop on the leaves 

 of apple trees and that this would give the insect a chance to be car- 

 ried over in case the fruit crop was a failure. 



Mr. Gillette cited an instance that had come under his observation, 

 where a hailstorm, late in May, removed all the fruit from the trees. 

 During the next two years the apples in orchards that were in the 

 area covered by the storm had been almost entirely free from worms, 

 while orchards lying just outside this area had their apples badly 

 infested. 



Mr. Cooley expressed the opinion that this moth was very suscepti- 

 ble to changes in temperature in the spring, and that this accounted 

 for the overlapping of the broods. He had placed an unimpregnated 

 female moth in a bottle in his refrigerator, and after two months it 

 had been removed and placed in a window during a warm day. The 

 moth revived and at first was very active, but died after a short time. 



Mr. Sanderson suggested that the second spraying be made a little 

 later in the season and believed that it would give better results. 



The next paper presented is as follows : 



A NEW ENEMY TO THE PLTJM, DIMORPHOPTERYX PINGUIS. 



By James Fletcher. 

 [Withdrawn for publication elsewhere.] 



AFTERNOON SESSION, TUESDAY, DECEMBER 29, 1903. 



The meeting was called to order by Doctor Fletcher, and the follow- 

 ing paper was presented : 



SOME ECONOMIC CONSIDERATIONS WITH REFERENCE TO THE 



TABANID^l. 



By James S. Hine, Columbus, Ohio. 



An interesting entomological stud}^ is that which has for its object 

 the separation of beneficial and injurious species, but it is safe to say 

 that one is almost sure to meet with perplexing questions when he 



