226 Transactions. 



Art. "KKYX-^Bionomic Observations on certain New Zealand Diptera. 



By David Miller. 



[Read before the Otago Institute, 8th June, 1909.] 



This paper is composed from the notes on tlie Diptera whicli I have col- 

 lected in Otago during the last two seasons.* The species dealt with are to 

 be found described in the " Synopsis of the Diptera Brachycera of New Zea- 

 land " (Trans. N.Z. Inst., vol. xxxiii), by the late Captain Hutton ; those 

 described elsewhere have the references attached. Only a few of the 

 more common species are figured in colour in this paper, as diagrams 

 and coloured plates of all the species will appear later in a series of papers 

 which I hope to publish, dealing with both new species and those flies 

 already described by Captain Hutton. Where it is deemed necessary, I 

 insert a brief account of the general characters and habits of the famiUes. 



I am indebted to Professor Benham for his invaluable suggestions during 

 the preparation of this paper. 



To avoid repetition I shall here give a description of the general fea- 

 tures of the localities mentioned : — 



Ocean Beach forms the ocean side of the isthmus connecting Otago 

 Peninsula with the mainland. This isthmus, which is about a mile in 

 width, is formed, for the most part, of blown sand and alluvium, and 

 is bounded on the opposite side to the beach by the mud-flats at tte head 

 of Otago Harbour. The sandhills of Ocean Beach are covered with lupin - 

 bushes and marram-grass. 



Tomahawk is separated from Ocean Beach by La\vyer's Head. Behind 

 the sandhills of Tomahawk is a lagoon into which run the streams from 

 the surroimding hills ; the overflow finds a course over the sand to the 

 sea. Lupin-bushes and marram-grass abomid. 



Purakanui is the district to the north of Otago Heads. The coast- 

 line of this locality is formed of a series of precipitous headlands with 

 intervening sandy beaches, behind each of which there generally exists a 

 mud-flat or swamp fed by streams originating from the hills. Of these, 

 Murdering Beach is a short strip of sand, surrounded by steep hills, and 

 backed by a swamp in which rushes and other forms of vegetation grow. 

 Long Beach is a stretch of sand of considerable length, and an extensive 

 area of cultivated land (often under water) exists behind the sandhills. 

 Mapotaki Beach faces the north (the last two face the north-east), and is 

 somewhat similar in form to the preceding, differing in the fact that the 

 sea gains an entrance to the mud-flat by a small stream which runs across 

 the beach after drainii:ig the swamp. The surrounding hills of Purakanui 

 are in places covered with what remains of the native vegetation. 



Mount Cargill (2,232 ft.) is situated toward the north of Dunedin, and 

 is still more or less covered by the native bush, which is either being felled 

 or burned off. 



* Owing to the loss of a note-book, the remarks concerning several of the species 

 mentioned below are somewhat meagre. However, since these observations went to 

 press, additional facts have been collected f(^r another paper, which I propose to publish 

 as soon as possible. 



