The Biology of the North American 



Crane- FHes (Tipulidce, 



Diptera) 



I. THE GENUS ERIOCERA MACQUAET 



c. p. alexander and j. t. lloyd 

 ithaca, n. y.* 



Introduction 



The tribe Hexatomini, one of the ten sections into which the 

 Tipulid flies have been divided, is widely distributed in the 

 north temperate and torrid zones. The dominant genus is 

 Eriocera, containing nearly one hundred described species, most 

 of which are tropical forms. No species have been described 

 from Europe or the Australian region but elsewhere the genus 

 is represented by a host of forms, the number of species be- 

 coming less as one goes north or south from the equator. The 

 males of many of the species have the antennae exceedingiy 

 elongated, extending backward twice the leng-th of the body. 

 The wing-coloration in the northern forms is sober, undiversi- 

 fied, but in the tropics the wings of many species take on a 

 banded or spotted appearance that is quite unparalleled in any 

 other group of crane-flies. 



The immature stages of this remarkable group of insects 

 were quite unknown hitherto. Van Roser (Verzeich.-Wuerttem- 

 berg. Dipt., pt. 1, p. 262) states that the larvae of Hexafonia 

 {=zAniso7nera of authors) live in the sand along the banks of 

 streams. 



The members of this tribe of insects seem to be easily recog- 

 nized in all stages. The adult flies, although closely resembling 

 the Limnophilini in venation, have the minimum number of 

 antennal segments for the family, there being but six of these 

 segments in Hexatoma and not more than ten elsewhere in the 



'Contribution from the Entomological Laboratory of Cornell University. 



