i6 Bernice P. Bishop Museum — Bulletin 



IMPORTANT IMMIGRANT INSECTS 



Among the instroductions by European commerce was the night mos- 

 quito (Culcx quinquetasciatus Say), a pest of first importance especially 

 as a carrier of disease. Though it has been generally understood that 

 these insects came to us from the coast of Mexico, it is interesting to read 

 the following account by Osten Sacken (ii8): 



About 1828-30 an old ship from Mazatlan, Mexico, was abandoned on the 

 coast of one of the Sandwich Islands. Larvae of Culex were probably imported 

 in the water-tanks upon it. The natives soon became aware of the appearance 

 round the spot of a — to them unknown — blood sucking insect ; it so far excited 

 their curiosity that they used to congregate in the evening in order to enjoy the 

 novelty. Since then the species spread in different localities, and in some cases 

 became a nuisance. 



This was related to me by Mr. T. R. Peale, the well known American ento- 

 mologist and artist, who visited the Sandwich Islands a few years later with the 

 United States Exploring Expedition under command of Captain C. Wilkes 

 (1838-40). A distinguished American, who spent many years on the islands and 

 whose acquaintance I made in Washington, confirmed the story to me, and told 

 me that he remembered positively that there were no mosquitoes on the islands 

 about 1823. 



This version is at any rate more probable than another which I read in the 

 German periodical, "Die Natur," that gnats were intentionally imported into 

 those islands by a mischiveous sea-captain, in vengeance against the inhabitants. 



Another pest of importance in Hawaii is the sugar-cane borer, Rhab- 

 docncmis obscurus Boisd., which was evidently introduced from some of 

 the Pacific islands; Boisduval (20) in 1835 described the species from 

 New Ireland and Fairmaire (32) later recorded it from Tahiti. This 

 borer began to make inroads upon the sugar industry of Hawaii apparently 

 (hiring the early eighties (107, 113), rapidly spreading until brought 

 under control by the introduced tachinid parasite (Ceromasia sphenophori 

 Vill.). The species was recorded by Blackburn and Sharp (120) with a 

 few brief systematic notes. The first careful study of the life history and 

 economic relations was that by C. V. Riley (132), the specimens being 

 sent to this celebrated entomologist at the request of his Majesty, King 

 Kalakaua. 



Another cosmopolitan insect found in Hawaii during recent years, 

 though of little economic importance compared with the cane borer, is the 

 milkweed butterfly, Daiiaida archippus Fab. This insect was not mentioned 

 by any of the early voyagers and in fact the first reference to its presence 

 in the islands is from Blackburn's material in 1878 (74). The geographi- 

 cal distribution of this .species was reviewed in 1886 by Walker (126), who 

 stated that these butterflies were abundant and well established in Hawaii 

 at that date. 



In the early nineties exotic scale insects began to command attention 

 (134) and during the following decade fully fifty species had been re- 



