424 NATUKAL HISTORY OF HAWAII. 



order should be, l)ut in the ease of the Hawaiian fauna the order, as treated 

 by Dr. Perkins, lias l>een made to include insects familiarly known as laee- 

 wiuged flies or hemerobians,"^" the dragon-tly,'"^' the book-lice'" and the 

 white ants or termites." - 



To this suf)er-order have been referred at least 116 species of insects. 

 About one-half of this number is made up by the lace-winged flies. They are 

 slender-bodied, delicate insects of small size, the largest measuring scarcely 

 more than an inch in length. They all have dainty membranous wings of 

 various colors as gray, brown, yellowish-brown, hyaline, iridescent, and often 

 pale green, the last color being the one most liable to attract attention. 



The lace-winged flies are forest dwellers and nocturnal in habit. The 

 common lace-winged fly"^ is quite frequently met with in gardens and shady 

 localities, and may be easily capt\ired. 



Of the dragon-tiies,"* at least one genus,"'' with tweiit.v-six endemic 

 species, may be regarded as of very long standing in the islands. The mem- 

 bers of this genus are all fond of the mountain forests and seldom occur at 

 lower levels. They have very slender bodies, with both pairs of wings shaped 

 nearly alike. So extraordinarily fragile, delicate and dainty are their wings 

 that they are often called Hawaiian damsel flies. Their gentle and airy man- 

 ner as they flit from leaf to leaf make them among the most attractive of the 

 Hawaiian forest insects. There are from seven to ten species on each island, 

 but at least two of them "" occur throughout the group. As a matter of fact, 

 the species of the genus are related to one another in such a way as to indicate 

 that they all have originated from a single ancestral species that doubtless came 

 to Hawaii in very remote times. 



The nymphs of some if not all of the species belonging to this genus 

 develop in the cups formed at the base of certain leaves in the forest, and can 

 live with a very scant supply of water. Living specimens confined in collect- 

 ing bottles continue active for several hours. 



They are aquatic and predaceous in habit in every ease, and are sure to 

 attract attention with their rapid darting movements, their strong legs and 

 jaws, and conspicuous eyes. The adults often flock to mountain pools during 

 dry seasons, as they prefer moist localities. As a result, their dead bodies are 

 often seen floating on the surface of the water. 



Of the three other genera of Odonata found in Hawaii, the biti blue dr;igon- 

 fly "" is the most conspicuous and abundant through the allied species -. the 

 strenuous dragon-fly"* is common enough, but so strenuous indeed that it is 

 difificult to capture specimens. The yellow dragon-fly "" is the common species 

 seen in the open country everj-where, but notably in the streets and gardens of 

 Honolulu. At the proper season a.s many as twenty may be seen at one time 

 hovei'ing (iver a s(iuare rod of lawn. 



Another sjiccies of iiinaii,'-" as all di'agon-flii's are callecl by the Hawaiians, 



^^^ Hemerobiidte. ^^'^ Odonata. ^^^ Psocidm. ^^- Tennitidie. ^^^ Chrt/soija inii-ropln/a, 

 ^^* Odonata. ^^'' Affrioii. ^^'^ Agrioti xanthomelas and A. parifirmti. ^^~ Atia.v jiniius. 

 118 Anax strenuus. n" Pantala fiavesceuH. i-" Trainea lacerata. 



