1912.] NATURAL SCIENCES OF PHILADELPHIA. 235 



ON THE ORTHOPTERA FOUND ON THE FLORIDA KEYS AND IN EXTREME 



SOUTHERN FLORIDA. I. 



BY JAMES A. G. REHN AND MORGAN HEBARD. 



It has been the desire of the authors for some time to determine 

 what species of Orthoptera were to be found throughout the winter 

 in the subtropical area of southern Florida. With this end in view, 

 the junior author visited the region in the latter part of March, 1910, 

 as it seemed evident that this would be the time when species would 

 have entirely disappeared, should they succumb to the colder weather 

 in this region, while spring forms would, as a rule, not have reached 

 maturity. The facts obtained would indicate that a considerable 

 proportion of the species of this region are in evidence throughout 

 the winter, though probably in considerably reduced numbers. 

 The amount of this reduction cannot be stated at present, as insuf- 

 ficient work has been done in this region during the summer. The 

 families Mantidae and Tettigoniidse, however, alone seem to be 

 severely affected by the cold, and the few specimens taken which 

 belonged to these families were either most battered remnants of 

 the past summer or the first freshly emerged individuals of the 

 spring brood. Nymphs of a number of interesting species were far 

 more abundant than adults of the same, while nymphs of several 

 species plainly unknown to the United States were taken, unfor- 

 tunately in such an early stage of development as to make determina- 

 tion impossible. It is the intention of the authors to do considerable 

 work in southern Florida during the summer of the present year, 

 and not only is it hoped that adults of these very interesting species 

 may be secured, but also that the publication of the results, when 

 compared with those given in the present paper, will indicate the 

 difference between the abundance of forms in the summer and 

 winter throughout the region. 



The following table will indicate the comparative abundance of 

 forms as found just before the appearance of the spring forms. 



Number Very Small 



of abun- Abun- num- Very Nymphs 



Family. species, dant. dant. bers. Rare. rare. only. 



Forficulidae 5 13 1 



Blattidae 9 12 13 2 



Mantidae 2 2 



Phasmidae 3 1 11 



Acrididae 23 1 11 6 1 1 3 



Tettigoniidse. 5 — 113 — 



Gryllidae 18 2 4 5 1 5 1 



