A. N. Cheney, « Angling Notes, Caddis Larvae », Forest and Stream, vol. LV, n° 18, New York, 29 septembre 1900, p. 251.
Having answered the queries propounded by Mr. Hough to the best of my ability, I will return the compliment by asking him a question. He says on the sheet of Forest and Stream al ready specifically mentioned : « One discovery Mr. Wood made which is of interest. He found his trough full of little sticks of wood at which his baby trough nibbled eargely. He broke open the supposed sticks and found each to be the case of a big grub or worm. Breaking up these things, he found his trout eagerly eating them . Then his discarded liver and the like and fed on these larvae. He had no dead lake trout after that, and this last year he raised nearly the entire hatch, whereas last year he list half . »
Indeed this is of interest,but I would like a few frills added to the bald statement that baby trout wre fed on caddis larvae. How old were the trout when they were first fed on the larvae ?- for they cannot eat solid food for some little tima efter the yolk sac is observed ; and if Mr. Hough will turn to page 109 of the report of the Fisheries, Game and Forest Commission for the year 1895 he will find the figures of an assortment of caddis cases-shell, bark, sand, wood, etc.- and also an enlarged caddis worm ; but I had a line put by the side of the enlarged figures to show the exact length, and a foot-rule will show that the line in three-fourths of an inch long. Baby trout will eat the worms all right enough, but they must be larger than fry that have just absorbed the umbilical sac. Furthmore, how many trout were reared on this kind of food, and how big were the trout before they took the case and the worm in its entirety ? Adult trout do not require to have their worms shucked, and I once explained in this paper that trout with sand in their stomachs did not take the sand for ballast, as was claimed, but had been eating caddis worms encased in sand.
Last season a friend furnished we with a lot of caddis larvae from his private trout pond to transplant for trout food, and recently I mentioned the great flight of caddies flies that I found on the Niagara River and a similar flight on the St. Lawrence ; but I would hesitate about taking the contract to suply caddis larvae for two or three millions of young trout in the State hatcheries ; and as for breaking up the cases. I fear the men would elect to grind liver instead, even if the larvae could be procured in abundance. If the liver, after grinding, is forced through a fine sieve to remove all stringry portions, there should be not great danger of killing young trout- at least there is no trouble of that sort in the New York hatcheries. Caddis larvae is a great food for trout and other fish, and there are some fifteen species of caddis flies, and while I have advocated the transplanting of the larvae to stock waters where the insect is not found naturally, I never heard of feeding larvae in a hatcherey to young trout, and the man who has an abundance of this food in his hatchery is fortunate ; but I fear it will not serve to feed fish on a great scale ; but if it will I desire to know more about the details. The expression « Found his troughs drifted full of little sticks of wood » is confusing. Supply pipes to a hatchery trough should not admit sticks of wood, for every effort is made to keep the water free of foreign substances by using screns and cheeses cloth, but troughs are certainly the abiding place of trout fry after they are hatched and for a part of the time that they are fed on liver emulsion. This subject of natural food is one of the hobbies I ride, and Mr. Hough wull place me under obligations if he will get from his friend more of the details of how the larvae is procured, prepared and fed to the rout, as well as the age of the trout the the feeds.