6 Transactions. — Miscellaneous. 



house-fly (Musca domestica, L.). The early settlers recognised 

 the beneficial agency of the intruder, and carried it from the 

 ports to the interior in paper cages. 



In many districts the common mosquito, the sand-fly, and 

 the small native flea have disappeared under the beneficial 

 results arising from drainage and other improvements of a 

 similar character. 



Amongst indigenous insects which have increased to a 

 large extent owing to the more copious supply of suitable food 

 afforded by introduced plants, whether naturalised or culti- 

 vated, three species of Coleoptera deserve special mention. 

 The grass-grub {Odontria zealandica, White) in the larval 

 state is terribly destructive to the roots of grass, and has 

 increased to a marvellous extent with the progress of settle- 

 ment. The grub takes the place occupied by the cockchafer 

 {Melontha vulgaris, Steph.) in Europe, but the perfect insect is 

 less destructive, although occasionally injurious to fruit-trees. 

 (In all probability 0. hrunneum, Broun, is equally dangerous.) 

 A small beetle {Colaspis imncticollis , Broun), now occurs in 

 vast numbers, the perfect insect feeding upon pome fruits, and 

 doing much damage. The native borer {Mmona Jiirta, Fabr.) 

 is another destructive insect unhappily now occurring in vast 

 numbers. In its larval state it bores galleries in the trunk 

 of Olearia solandri (Hook, f.), Cassinia retorta (A. Cunn.), and 

 effects a comparatively small amount of injury ; but when 

 citrads or other fruit-trees are attacked the galleries are more 

 numerous and more extensive. In some localities it has for- 

 saken the Cassinia, &c., and evinces a marked preference for 

 the lemon, orange, and lime. 



Amongst introduced Mollusca must be enumerated the 

 common snail {Helix aspersa, Miiller), which, from its depre- 

 dations in the garden and field, has become a pest throughout 

 the colony. It is generally agreed that several of the smaller 

 native Helicid£e have become rare since this shell was first 

 observed in x\uckland, about 1868 ; but there is no direct evi- 

 dence to show that their diminution has been caused by their 

 lai'ger and more robust congener, although in some cases their 

 food-supply must have been diminished by its ravages. The 

 common garden-slug [Leinax agnstis, L.) and the large brown 

 slug {Arion hortensis, L.) are generally naturalised also, but 

 are not nearly so destructive as the Helix. Limncea stagnalis 

 (L.) is abundantly naturalised in the Avon at Christchurch, 

 and may have some connection with the comparative infre- 

 quency of the smaller native molluscs in that river. 



Fishes. 

 There is no evidence to show that the few native fresh- 

 water fishes have suffered from the introduction of the Prussian 



