FEED SUPPLY FOR TROUT.

New Zealand Herald, Volume LXIII, Issue 19235, 26 January 1926, Page 10

FEED SUPPLY FOR TROUT.

A SERIOUS DIMINUTION. THE BACKWARD NATIVE FLIES. [BY TELEGRAPH. OWN CORRESPONDENT. ] CHRISTCHTJRCH, Monday. Dr. R, J. Tillyard, chief of the biolo- [ gical department of the Cawthron Insti- ; tute, Nelson, addressed the North Canterbury Acclimatisation Society on trout feed in New Zealand. He said there were some species of the mayfly in New Zealand which were more primitive than the English type of- insect. They had no' quick movement and did not dance on the surface of the water. From the point of view of evolution the New Zealand mayfly was two or three million years behind the English' insect, but now they had been almost eaten out by the trout. The caddis fly was a most important item in the food of the trout. These insects made cases to protect themselves and carried them about. Th'ey fell ready victims to the introduced trout. There was a magnificent food supply in New Zealand, but it could not stand up to the trout. Where the fisheries were deteriorating it was simply because the feed was eaten out. The* insect supply had been seriously diminished. It was possible, but exceedingly difficult, to get a larger supply of insect food. In the New Zealand rivers there was a tremendous waste of potential trout feed, which was turned int.o sandflies. The cure was to find a suitable insect which would feed on the sandfly larvae and turn itself into trout feed.

Dr. Tillyard stated that during his coming visit to England, America aad Europe he intended among other things to see what could be done in the way of finding a better 'supply of feed for trout. The New Zealar 1 rivers were very young, and always charring their courses. "Plant alongside the banks and you will nc<f'er find the Avon running out of its course," said the speaker.