426 NATURAL HISTORY OF HAAVAII. 



of recent introduction. The red-bug family **^ lias a single introduced species: 

 the family Mijodocliidce has a number of species, among them the several mem- 

 bers of the Hawaiian genus Xysius — insects less than six milimeters in length. 

 The curious Lantana bug,!^^ purposely introduced, is the only representative 

 of its family i-''' in the islands. The damsel-bugs, i^"* so called for want of a 

 better name, are well represented by several Hawaiian species belonging to 

 a large genus. '^•"' The assassin bugs''^" have won their popular name on ac- 

 count of their predaceous habits. A dozen species, most of them of fair size, 

 and usually of wide distribution, occur in the islands. The large assa.ssin 

 ]jygi37 Qj. ijissing bug, is thirteen millimeters in length, and is doiibtless an 

 American species that first appeared in Hawaii about 1897. The minute, 

 slender-bodied Miridce are represented by several species of small insects, 

 belonging to a number of genera, none of Avhieh are liable to be seen by casual 

 observers. 



Conspicuous among the few species of insects that live on or within the 

 water in Hawaii is the representative of the family of water-boatmen. ^■'■'* It 

 is represented liy a snuill oval, gray and black mottled species i*" that has the 

 body flattened above and .sM-ims on the ventral surface. This peculiar habit 

 is of value to the novice in identifying them, since in this they dift'er from the 

 next family, in whicli the various species all swim on their backs. 



When the water-boatmen swim througli the water they are almost com- 

 pletely eiivclii|>('d in air which gives them a silvery appearance. If they stop 

 swimming or lose their hold on the bottom they quickly come to the surface, 

 as their bodies enveloped in air are much lighter than the water. They occa- 

 sionally float on the surface of the water, or sluwiy paddle about with their 

 oar-shaped legs. When they choose they can leap i'vmn the water into the air 

 and tiy away. They feed principally on other insects and lay their eggs upon 

 water plants. 



The back-swimmers, ^"'i like the foregoing family, are represented by a 

 single species ^^^ that happens to be one of wide distribution. The favorite 

 attitude of the back-swimmers is floating on the surface of the water back 

 down, with their long oar-like legs stretched outward and forward ready for 

 making a sti-nkc. When disturbed they will dart out of the way, usually by going 

 rapidly to the bottom, there to remain hidden for some time. Other minute 

 bugs,'"'- with minutely-spotted wings in the adult and with a red edge to the 

 abdomen in the iinmature stage, that walk about on the water, especially in 

 stagnant, weedy pools, are very comnion. They belong |o a totally different 

 family 1*-^ of insects from either of the two species just described, and in turn 

 may be easily confused with rarer species of bugs and flies that frequent sim- 

 ilar places. 



^■'^ Pfirrhticoridce. ^'"' Teleomtiia lantanm. ^^^ Tinguidcp. ^'** Nabidw. '-'^ Fednri<)lus. 



^^'^ RedufiidCE. ^^"^ Zflua renardii. ^''^ Corixida!. ^^^ Aretocorisa hlarkhiinii. ^**' ytitom'rtidir. 



**i Buetioa pallipes. ^*- Microvelia vai/ans. ^*^ Gerridw. 



