23 



aMUiially ami prohaljly ii<i iiiorc .Mr. (tillcttc liad t'oiiiid lliaf tlie 

 lir.sl brood extends over about sixty-nine days— Ihal is, the mollis 

 from tliis brood luive continued to emerge for that numl)er of (hiys at 

 I'ort Collins. 



Doctor l'"'let('her called attention to the fact thai t lie difVei'enc(' in 

 llie time of hatching of eggs is veiy common in nature. Ten days' dif- 

 fciciK-e in the time of egg laying might have considerable bearing on 

 llie date of maturity of the jirogeny. Larva* halcliing early miglit 

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

 winter. He referred to the fact tluit Mr. C. 15. Simpson liad proved 

 that tlie larva' of the codling motli were able to develop on the leaves 

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

 lied over in case the fi-uit crop was a failure. 



Mr. GilU^tte cited an instance that had come under liis observation, 

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

 During Die ne.vt two years the apples in orchards that were in Hie 

 area covered by the storm had been almost entirely free from woi-ms, 

 while orchards lying just outside this area had their apples badlj' 

 infested. 



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

 ble to changes in temperaturi* in the spring, and that this accounted 

 for the overlapiiing of the liroods. He had phiced an unimi)regnated 

 female moth in a ])ottle in his refrigerator, and after two months it 

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

 moth 7-evived and at first was very active, but died after a short time. 



Mr. Sanderson suggested that the second sj^raying be made a little 

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



The 7iex1 papei- presented is as follows: 



A NEW ENEMY TO THE PLUM. DIMORPHOPTERYX PINGTJIS. 



By James Fletcher. 



[Withdriiwn for iin1>li<ati<>Ji elspwhero.] 



AFTKR.XOOX SFSSinX. T(^h:si>AV. I)F.< 'KMliKR :?9. 190.'?. 



The meet ing was called to order iiy Doctor l-'letchei, and the follow- 

 ing i)apei- was presented: 



SOME ECONOMIC CONSIDERATIONS WITH REFERENCE TO THE 



TABANID^. 



By J.x.Mivs S. Hike, ('itliiiiilms. Ohio. 



An interesling entomological stud>' is thai whirli has for its object 

 the separation of ln'iielicial and injurious species, but it is safe to say 

 that one is almost sur«' to meet with i»erplexing ([uestions when he 



