Iviii FAUNA HAWAIIENSIS 



CXlVIll 



that have always been well known to the natives, on account of the periodical abundance 

 of its larvae. These are truly ' army-worms ' marching over great areas of pasture land 

 and devouring all the herbage on their march. Of late years these great armies have 

 been much less frequently noticed, though formerly of annual occurrence at the season 

 of the growth of fresh grass. There is no doubt that this diminution of the ravages of 

 the grass army-worm was due to the excessive multiplication of the imported Indian 

 mynah bird [Acridotheres tristis), great flocks of which visited the pasture lands to feed 

 on the caterpillars. Of late years it would appear that the mynah bird has become less 

 numerous, owing to the failure of lantana berries, which formed its chief supply of food 

 throughout the year, and it is said that, coincidently with this decrease, the army-worm 

 has again occasionally become conspicuous in some pastures. Previous to the great 

 multiplication of the mynah bird, this Spodoptera was a favourite and important food- 

 supply of the golden plover during the winter months. It is well known that, when 

 feeding on the hordes of caterpillars, these migrants from Alaska arrived at their finest 

 condition, before leaving the islands for their distant breeding grounds. 



Of the two species of Caradrina, C. rechisa is a recent importation, no doubt from 

 Fiji, as we have seen its larvae on consignments of plants from those islands. It was 

 first found in Honolulu in 1903 and soon became common, and extended its range to 

 other of the islands. C. exaininis, once found on the island of Hawaii, is probably also 

 a foreign species. 



Plusiadae. — The two genera Simplicia and Adrapsa are each represented by an 

 introduced species, both of them occurring in Fiji, and we have found the larvae of both 

 swarming on plants imported from that group. The Simplicia was imported long before 

 the Adrapsa, which was not noticed until after 1902. 



Nesamiptis, with two species, was described from the islands, but I believe exists in 

 tropical Australia. One of the species (A^. obsoletd) is extremely common and most 

 variable in colour and pattern of markings. Its caterpillars feed very freely on the 

 imported ' Hilo' grass. The other, N. plagiota, is much more local, though sometimes 

 common, and appears to vary very little as compared with its congener. Hypenodes, 

 with seven species, has one which is very widely distributed and abundant, and also 

 very variable (//. altivolans). It is freely attracted by light and to sugared trees and 

 may often be observed in great numbers flying at dusk in marshy places in the 

 mountains amongst sedges. Most of the other species frequent very wet forests, and 

 are much less numerous and less commonplace in appearance. 



Of the two species of Cosmophila one is probably introduced, as we have found its 

 caterpillars on plants brought from Fiji. Both exhibit much variation, but in the case 

 of the foreign C. sabulifera, variation is local or irregular. In one instance a number 

 of caterpillars, taken on a native Hibiscus (?) in a mountain forest, produced a very 

 variable series of adults, including some remarkable aberrations. On another occasion 



