OF WASHINGTON. 219 



R. S. Clifton were present, the small attendance being due to a 

 blizzard. 



The Corresponding Secretary announced the deaths of Berthold 

 Neumogen and George D. Bradford, both of New York city and 

 both corresponding members of the Society. 



On motion, the President appointed Messrs. Schwarz, Howard, 

 and Gill a committee to take charge of the sale of the collection 

 of Arachnids left by the late member of the Society Dr. George 

 Marx, as well as to prepare a biographical sketch and a list of 

 his writings for the proceedings. 



Mr. Coquillett was elected a member of the Executive Com 

 mittee to fill the vacancy caused by the death of Dr. Marx. 



Mr. Howard read a paper entitled 



NOTES ON THE GEOGRAPHICAL DISTRIBUTION WITHIN 

 THE UNITED STATES OF CERTAIN INSECTS INJURING 

 CULTIVATED CROPS. 



By L. O. HOWARD. 



The broad subject of the natural geographical distribution of 

 animals and plants is a sufficiently complicated one, but it be 

 comes still further complicated when we come to consider the 

 actual and possible distribution of cultivated species. One small 

 phase of this subject enters naturally into the work of the eco 

 nomic entomologist, although it has as yet received no attention. 

 This phase is expressed in the query, How far will a given inju 

 rious insect follow its natural food-plant when the geographical 

 range of the latter is extended by artificial means? This is a 

 question which can be answered satisfactorily only by a study of 

 each individual injurious species and the facts concerning its ori 

 gin and present spread, as well as by a consideration of the laws 

 governing the distribution of the. food-plant. 



It is reasonable to suppose that in many cases insects will be 

 unable to follow their food-plants to the limits of their possible 

 range, notwithstanding the fact that the geographical distribution 

 of animals and plants is governed by the same general laws of 

 temperature, humidity, exposure, and geological characteristics. 

 The obvious reason for this is, that purely artificial features are 

 introduced in cultivating plants, varieties are propagated which 

 develop resistant powers lacking in the parent stock ; seeds, in 

 the case of annuals, are carefully collected and selected, the soil 

 is prepared for their reception, and is artificially fertilized; 

 while with perennials the same general care is taken. It fol- 



