I 



INTRODUCTION ccxv 



of other trees, and arranged in regular rows in these slits. They were observed 

 numerously as early as 1895 or perhaps earlier, but the adult insect, which is compara- 

 tively rarely met with, was not found till a much later period. Probably the eggs will 

 prove to be much parasitized by the Anastatus above mentioned. Eggs of apparently the 

 same cricket have been found in shoots of young plants brought from Hong Kono- and 

 Japan. The other imported Locustid, Xipliidium varipemie Swezey [ = X. fuscitm 

 huj. op. II. 14), was a very rare and local insect in 1892, and by no means numerous in 

 1897, but by 1900 had become one of the most abundant of insects and spread all over 

 the group. Probably it will prove to be an introduction from the western parts of 

 N. America. It is to a very large extent carnivorous, devouring Homopterous insects 

 and caterpillars. It is a delicate feeder on vegetable matter, preferring the stamens 

 and other tender parts of flowers. The eggs are laid in a row beneath the leaf-sheath 

 of Hilo grass, sugar-cane, Caiina, etc., and are frequently destroyed by an Aphelinine 

 parasite [^Paraphelinus xiphidh) of abnormal habits, of which about a dozen examples 

 may emerge from a single egg. For some years after its appearance no short-winged 

 forms of the Xiphidinin were noticed, but subsequently they became abundant. In the 

 driest and hottest localities the short-winged forms appear to be absent or nearly so 

 during the hottest months of the year, but appear numerously at other times. 



Swezey has investigated the percentage of long-winged and short-winged forms in 

 various localities and in various months of the year. Intermediate forms are very rare, 

 usually about 2 per cent., where the proportion of winged and flightless examples is 

 about 83 per cent, and 15 per cent. ; whether the greater percentage consist of the 

 long-winged or short-winged forms the percentage of intermediate forms reinains much 

 the same. 



The other Locustidae are endemic and are represented by a single Conocephaloides 

 (C. remotus Walk. = C. lunvaiicnsis huj. op.), while eight or nine species belong to the 

 endemic genus Banza {Brachyiiietopa huj. op.). The former seems now to be very 

 rare, but was probably once abundant, and has been destroyed by introduced predaceous 

 insects. It is interesting, as being a form such as one might suppose gave rise to the 

 more remarkable Banza. All the species of Banza (except that possibly B. niolokaiensis 

 and B. inauiensis may prove to be synonymous) are each one restricted to a single 

 island of the group, and all those species, of which a number of examples have been 

 collected, are dimorphic, having green and brown forms. The most remarkable case 

 of this dimorphism is exhibited by B. parvula W. {discolor Redt.), where the whole 

 appearance of the insect is changed owing to the coal-black face of the discolor var. 

 and the pale face of the blackbiirin form. Further reference to this species will be 

 found in Vol. 11. p. 689 of this work. Briefly it may be said that in the localities, 

 where it has been specially studied, the males of B. paii'ula are brown, black-faced 

 insects, with green pale-faced forms occurring rarely, while the females are pale-faced 

 green insects with black-faced brown coloured individuals occurring still more rarely 



