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their abundance of recent years for one or more seasons to come, unless 

 unknown influences are involved. 



We can scarcely expect future scarcity of the corn- ear worm unless 

 another severe and blizzard-marked winter is in store, as this insect 

 increased in numbers with the advance of tbe season until, toward the 

 closing days of September, it was fairly abundant in corn fields, though 

 not injurious in gardens. The immediate future of the American 

 locust is also doubtful. Both of these species are strong fliers, and 

 favorable winds might bring either in considerable numbers and to a 

 great distance northward in a year or two and the two species again 

 be as common as ever. 



NORTHERN SPECIES APPARENTLY BENEFITED BY COLD WINTERS. 



This brings us to the subject of the species which are more at home 

 in colder regions, and which were apparently benefited by the cold 

 spell in their hibernation. A study of the insects affecting strawberry, 

 blackberry and other rosaceous garden crops in the vicinity of the Dis- 

 trict of Columbia goes to show that we have in this region only one 

 species which is really of prime importance in ordinary years, the straw- 

 berry weevil, which it might be mentioned was reported injurious 

 the past year as in nearly every year for the past decade and more. 

 The other insect enemies of these crops are, with scarcely an exception, 

 Northern species, and we may expect a continuance and possibly an 

 increase of these provided the cold weather prevails throughout the 

 winter 1899-1900. The same is true of the insects which affect the 

 currant and gooseberry, only one of which, the imported currant worm, 

 has been noticed injurious in this vicinity in recent years. 



SOME GENERALIZATIONS. 



Finally, I wish to emphasize a remark made by Dr. Howard in a 

 discussion of the geographical distribution within the United States of 

 certain insects injuring cultivated crops and brought out in referring to 

 the American locust (Proc. Ent. Soc. Wash., Vol. Ill, p. 225), which my 

 own observations substantiate. It is that in certain forms of insects 

 the winter temperature must have some effect in determining distribu- 

 tion. While admitting that the past winter was exceptional as regards 

 temperature, the writer feels confident in carrying conclusions still far- 

 ther in stating that in his opinion, based upon the study of the effect 

 of that winter on injurious Northern and Southern forms of insects 

 occuriug in that portion of the Carolinian or humid life areas of the 

 Austro riparian and Alleghanian zones (a climate like that of the Dis 

 trict of Columbia), mean winter temperature has more effect upon deter 

 mining the rarity or abundance of these species thau has the mean 

 summer temperature. These observations tend to show, also, what has 



