Selection of materials for case-buiding

Hilmy M. Hanna, « Selection of materials for case-buiding by larvae of caddis flies (Trichoptera) », Londres, Proceeding of the  Royal  Entomological  Society., (A) 36, 1961

Little work has been done on the selection of materials for case-building by caddis larvae. The majority of published observations are brief and unsupported by detailed experiment work.

Buchner (1905) considered that Drusus selected pine needles and Limnephilus stigma Curtis seeds of water plants because these materials were distasteful to predators, but he gave no evidence to support this. Bierens de Haan (1922) showed that the larvae of L. marmoratus Curtis preferred spruce needles to other material. Uhlmann (1924) found that young larvae of Phryganea grandis L. preferred stems to other material, although they were able to use leaves or sand in the absence of stems, and he suggested that this preference might change as the larvae grew older. Dodds and Hisaw (1925) thought that the selection of materials might be based on the form and size of the pieces. Gorter (1929) showed that the larvae of Limnophilus flavicornis (Fab.) preferred pine needles to other materials. Brues (1930) thought that vision might play an important role in the selection of the shining opal flecks which he found in the cases of Hesperophylax magnus Banks. Gorter (1931) studied the selection of materials by 11 species of caddis larvae and founds that older larvae showed a narrower range of choice than younger ones. Scheffler (1932) suggested that the choice of materials might be determined by the nature of the water in which the larvae lived. Uhlmann (1932) suggested that whether a larva selected sand or plant material was determined genetically. Dembowski (1933) measured a few sand grains at the anterior and posterior ends of the case of Molanna angustata Curtis and concluded that the larva selected larger sand grains as they grew older. Moretti (1934) showed that colour did not play an important role in the selection of materials by L. rhombicus (L.), Glyphotaelius pellucidus (Retzius) and Sericostoma personatum (Sprnce) and he thought that shape and dimension were more signifiant. Fankhauser and Reik (1935) suggested that larvae of Neuronia postica Walker preferred material that could be used without cutting, and they observed that the larvae preferred dead leaves to all other materials. Copeland and Crowell (1937) noted that a species of Limnephilus selected material of suitable length. Fritsch (1941) gave L. flavicornis and L. bipunctatus Curtis sand grains of four grades sizes and found that certain sizes were preferred. Dudziak (1950) suggested that the thickness of the material was a significance in selection by larvae of Phryganea obsoleta Hagen. Staropolska and Dembowski (1950) observed that M. angustata selected larger pieces of chicken egg shells for building the hood than for the rest of the case. Maillet and Carasso (1952) bfound that the larvae of Triaenodes conspersa (Rambur) preferred rigid twigs of small diameter for building the normal case.