cxcii FAUNA HAWAIIENSIS 



in the forest-belt, and eggs, nymphs, and adults may be found on all kinds of trees, as 

 well as on ferns and low plants. It has even been found breeding in gardens in the 

 town of Honolulu. Its chief food seems to be caterpillars, especially those of the 

 genus Scotorythra, but those of a good many other groups are also attacked occasionally, 

 e.g. Plusia, and various Pyralidina. During the excessive multiplication periodically of 

 looper caterpillars, Oechalia sometimes becomes also excessively numerous, and we 

 have then seen eggs, nymphs, and adults in countless numbers on the forest-trees. 

 During the worst years of the attack of the leaf-hopper of the sugar-cane {Perkinsiella), 

 in some localities, in cane-fields adjoining the forest, numbers of Oechalia were to 

 be seen in all stages preying on the hoppers, and both species of the genus were 

 present. 



During a visit to Australia I only noticed occasional specimens of Oechalia, and 

 do not know whether, though known to become very numerous, it ever occurs in such 

 great numbers, as its Hawaiian congener, nor whether it exhibits the same structural 

 variability. It is proper to say that in certain localities it is quite possible to collect a 

 fair series of the Hawaiian species, that does not show much variation. Dark metallic 

 green forms of grisea with blunt spines seem mostly to occur in wet localities at 

 moderate elevations, and have been noticed especially in the West Maui Mountains 

 and on Haleakala. 



Thyreocoridae. — Geotomus pygniaeus is probably an introduced species, though it 

 would be of some interest to compare its variation with that of specimens from other 

 countries. It frequents open country, and is often found under stones, and thrives in 

 dry, hot localities near the coast, as well as in open spaces in the high forest, in the 

 regions where frosts occur. Nymphs are found in company with the adult at the roots 

 of herbage or beneath rocks. 



Coleotichus blackburniae is the sole representative of the Scutellerine group, and 

 is by far the most showy member of the Heteropterous fauna. It is not known from 

 elsewhere, but its congeners are conspicuous in Australia and the Moluccas. Apart 

 from the fact that it is the finest Hawaiian bug it is interesting, in that it appears to 

 have two forms, usually distinct at a glance, the one appearing red, the other yellow. 

 It is very widely distributed, and is found in hot, dry localities near sea-level, and in the 

 mountains to five or six thousand feet above the sea. I have bred specimens from 

 nymphs found in a garden in Honolulu. Both adults and nymphs are frequently 

 gregarious, lying packed close together, when at rest. Great numbers are sometimes 

 in consequence found together, and a single tree may hold some hundreds of specimens 

 of adults and nymphs of all sizes, as well as many eggs. The adults appear to be on 

 the wing at night, and occasionally enter houses, attracted by the light. However, 

 they take flight very readily on slight disturbance in the daytime, especially during hot 

 sunshine, usually flying a short distance, and making a loud humming noise as they fly. 



