SOME OBSERVATIONS ON INSECTS OF THE BETWEEN 

 TIDE ZONE OF THE NORTH CAROLINA COAST. 



By Z. P. Metcalf and Herbert Osborn. 



An opportunity for a brief study of the ecological condition 

 prevailing at Wrightsville Beach near Wilmington, N. C, 

 resulted in the determination of the ecological adaptation of 

 several species of Homoptera which have either been entirely 

 overlooked or so little studied that a record of our observations 

 seems worth while. The particular and very interesting eco- 

 logical situation common of course to long stretches of the 

 Atlantic coast but admirably exhibited at Wrightsville Beach 

 lies in the between tide zone of the inner beach adjoining the 

 sound. This differs from the outer beach facing the ocean in 

 that it is not subjected to the severe wave action of the exposed 

 coast while it gets the full benefit of the rise and fall of the 

 tides. This results in a most luxuriant growth of tidal grasses, 

 which are fully adapted to submergence some of them at levels 

 where the whole plant is submerged for hours at a time other 

 species less completely submerged and merging into the zones, 

 of Uniola which for the most part appear to be above the level 

 of the high tides although the roots and at time portions of the 

 stems are no doubt under water. 



These grasses support a multitude of insects among them 

 many Homoptera and these were the objects of our special 

 attention. The most abundan tof these were the delphacids 

 {Lihurnia detecta) but there were other fulgorids, some jassids 

 and one species of cicadid. These insects are fitted in varying 

 degrees to survive the periods of submergence to which they 

 must be subjected but all must have undergone some modifica- 

 tion in habit and probably in life history if not in structure to 

 fit them for this mode of life. 



It certainly seems rather novel to find these strictly aerial, 

 normally terrestrial insects associated with fiddler crabs and 

 seasnails and maintaining themselves under all the exigencies 

 of tidal forces and alternating aerial and aquatic life. Notes on 

 some of the species observed will illustrate some of the 

 adaptations. 



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