THE SCORPIONS OF THE WESTERN PART OF THE 



UNITED STATES, WITH NOTES ON THOSE 



OCCURRING IN NORTHERN MEXICO 



By H. E. EwiNG, 

 Of ihe Bureau of Entomology, United States Department of Agriculture 



INTRODUCTION 



During recent years many inquiries have been received in regard 

 to the identity, habits, and the seriousness of the stings of our 

 scorpions. Most of these have come from the Southwestern States 

 where scorpions are abundant and where the activities of the people 

 bring many of them in frequent contact with these venomous arach- 

 nids. Scorpions in this section of tlie country are a great annoyance. 

 Although serious cases of stinging have been few there, across the 

 border in northern Mexico many reports of serious consequences 

 following scorpion stings have been made. In the State of Durango 

 even death has been attributed to them. Because of these inquiries 

 and reports it was decided to investigate especially the scorpions 

 of the Southwest. This paper is the first to be prepared dealing 

 with them. In it a taxonimic synopsis is given of all the species 

 reported from the United States west of the Mississippi River. In 

 dealing with the more common species the distribution, as far 

 as known up to the present, has been given. Although but little has 

 been learned of the life histories, habits, and effects of the venom of 

 most of our species, that which is known is summarized. More com- 

 plete revisionary papers dealing with the taxonomy and literature of 

 the species occurring in North America are planned. 



Notes are frequently added concerning species occurring in north- 

 ern Mexico. These are of particular value since the writer has had 

 the opportunity of studying a large collection of scorpions taken in 

 Durango, Mexico and some other localities in that country by Dr. 

 W. J. Baerg, of the University of Arkansas. Also it is of much 

 im^Dortance to know if the species which are being reported as beingr 

 fatal to man in Durango occur within our borders and if so to 

 what extent and under what conditions. 



No. 2730.-PROCEEDINGS U. S. NATIONAL MUSEUM, VOL. 73, ART. 9. 



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