298 

 New Hawaiian Delphacidae. 



(Read December 14, 191(5.*) 



Duriiii>- the last twelve months considerable additions liave 

 l)een mad(> to our Delphacid ccdlections, several new species 

 liave been (•ai)tiircd and our knowledg-e of the food-plants of 

 many species has been corrected or extended. This has been 

 chiefly due to the energy of Messrs. P. H. Timberlake, O. H. 

 Swezey and W. M. Giffard. Mr. Giffard has also procured 

 a small but interesting* collection from the Island of Lanai. 

 This collection was made by Mr. G. C. Munro with the assist- 

 ance of H. Gibson and it brings the number of species known 

 from that island up to fifteen, and places it third on the list. 

 This indicates that the nund)er (»f s])ecies still unknown from 

 the three larger islands of Kauai, Molokai and Maui is very 

 great. 



The new s])ecies show the same degree of phallic differen- 

 tiation as do s])ecies previously described, in som- cases they 

 are closely related to known forms but in others they ai)pear to 

 be quite isolated. The Hawaiian species of Kelisia have been 

 considered as foreign : the four species belong to three distinct 

 t_\p(s which, without intermediate forms, cannot be conceived 

 iis having any relationship. Two species, A', sporoholirola and 

 A', sirczci/i. ai'c closely related, and it is probalde that (me is 

 of local origin. f. Fdsewhere^! I have ])ut forward the sugges- 

 tion that this ])hallic differentiation represents a diffei-entiation 

 of the germ-plasm and, although I have given the subject con- 

 siderable thought, T can offer no better reason. I believe that 

 one of the first steps in species formation among Hawaiian 

 Delphacidae is a change of food-])lant. In many cases this 

 will lead to isolation and may eventually lead to differentiation 

 of the germ-plasm. Mr. W. M. Giffard brought to my notice 

 the fact that certain species feeding u])on more than one food- 



* The captures, etc., have been brought up to date (February, 1917). 

 t Since this was written, K. paluditni Kirk, has been found to have 

 a wide range in the Pacific. 



t Pro. Haw. Ent. Soc. Ill, 1916, p. 210. 

 Proc. Haw. Ent. Soc. Ill, No. 4, May, 1917. 



