AMATEUR FISH CULTURE 



larvae which eat ova. This seems to be one of 

 the few cases in which nature is just, for caddis- 

 worms are taken very readily by even small 

 trout. Large trout will take them very greedily, 

 cases and all. Therefore, I should advise the 

 fish culturist to cultivate them as food for the 

 fish he is rearing, but to be very careful that 

 they do not get into the rearing boxes or hatch- 

 ing trays when he has ova in them. The caddis- 

 worms kill the ova by making a small hole in 

 them and sucking some of the contents out ; 

 from this hole some more of the contents escapes, 

 and as it comes into contact with the water be- 

 comes opaque. 



Caddis-worms are the larvae of an order of 

 four-winged flies commonly known as sedges, 

 caddis-flies, or water-moths. The latter appella- 

 tion is of course a misnomer, as these flies (Tri~ 

 diopter a) have nothing whatever to do with 

 moths. They resemble moths, however, in that 

 they have four wings which when at rest lie in 

 much the same position as do those of moths, 

 and as many of them have their wings thickly 

 covered with hairs, this resemblance is sometimes 

 very marked. The larvae (caddis- worms), being 

 eagerly sought as food by many fish, and having 



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