Ducweed

F. G. Bing, « Curious behaviour of Caddis-Worm », Londres, Science-Gossip, vol. II, n° 15, mai 1895, p. 82.

Mr. H. B. Guppy’s note on «  Caddis-Worms and Duckweed » (ante page 11) reminds me of a curious and amusing incident which took place in my aquarium last summer. I had three specimens of these larvae, and found great interest in watching their movements and habits. Two of them had cases composed entirely of sand grains and very small fragments  of other material, whilst the third was distinguished by the addition of a small twig and a piece of straw, bothof which overlapped the extremity of his case by about a quarter of an inch. I noticed that i twas continually followed about by one of the other caddis larvae, which was often to be found hanging on to the end of the twig. In about three days it had succeeded in detaching the portion of the twig that projected from its neighbour’s habitation, and was wearing it about upon its own back. Not even then satisfied, it shortly afterwards commenced a similar attack upon the piece of straw, and on securing possession of a fragment, perche dit sideways just over its head. I ought to mention that there was plenty of sand and pieces of water-plants eaten off by snails in the aquarium, so that lack of building material cannot be urged as the reason for this caddis worm’s behaviour.