HiijGENdorp. — Insect-lift at Cass Mountain Biological Station. 135 



Art. XI. -Notes from Canterbury College Mountain Biological Shit ion, 



Cass. 



X o . 6 . — The Insect-lif e . 

 By F. W. Hilgendorf, D.Sc. 



[Rnul befon th< Canterbury Philosophical Institute, 5th September, J'Jli , received hi/ 

 Editors, 31st December, 1917 ; issued separately, 24th May, 1978.] 



Introduction. 



Thk general descriptions which have been written of the physiography 

 and plant-associations in the neighbourhood of the station are essential 

 starting-places for, as well as stimulants to, more detailed study. With the 

 object of preparing a similar paper on the insect-life near the station I made 

 some collections during the summer and autumn of 1917. and arranged the 

 specimens thus captured in a small museum case deposited at the station 

 for reference by future students. The notes on the collection were at first 

 intended to be purely systematic, but it was soon recognized that the insects 

 were so noticeably a part of the landscape that they should be dealt with 

 in the order of their occurrence rather in that of their zoological classifica- 

 tion. Thus on tussock or in swamp or forest different associations of 

 insects are found, and in the following pages these associations are de- 

 scribed, and in some cases attempts are made to explain their relationships 

 to their environment. Of course, in dealing with several orders of insects 

 no attempt at a complete catalogue can be made even when only a small 

 area is under consideration, and so these notes deal only with the species 

 that from their size or numbers come readily under the observation of the 

 student. 



A. The Environment. 



The topography and physiography of the neighbourhood of the station 

 are described by Chilton* and Speightf. The variation in land and water 

 is such as to encourage a great diversity of insect-life. Within a radius of 

 little more than a mile from the station there are a lake, a swamp, a sluggish 

 stream, many rapid streams, a shingly river-bed, a stretch of open tussock 

 country, open shrub-land, shrubby thicket, patches of forest, and areas 

 of bare rock, with slopes of scree. Each topographic form is in general 

 associated with a special kind of plant-covering, and this, of course, forms 

 the dominant factor in the environment of the insect population. The 

 p>lant-associations are described by Cockayne and Foweraker,f and such 

 a description is essential as a basis for any attempt at detailing the modes 

 of life of the insects. 



The plant-life of the area is to a certain extent unaltered by the advent 

 of man. The forest, the shrub-land, and the river-bed and rock plants 

 are probably almost entirely primitive. Even the tussock-land has been 

 altered but little, and the alteration that has occurred seems more in the 

 direction of varying the proportions of the primitive plants than in their 

 replacement by introduced species. 



* C. Chilton, Notes from Canterbury College, .Mountain Biological Station, No. 1" 



Tru»s. X.Z. Ins!., vol. 47, p. 331. 1915. 



t R. Speight, ibid., vol. 48, p. 145. 1916. 



I L. Cockayne and C. E. Foweraker, ibid., vol. 48, \>. 166, L916. 



