Cinnamon Sedge

• The larva weaves a silk tube and coats it with fragments of leaves, stems and grains of sand gathered from the bottom, forming a portable house that it drags along and withdraws into when threatened.
• A French artist gave caddisfly larvae gold, pearls and precious stones instead of sand, and the larvae built cases from them that are exhibited as works of art.
• It is an essential decomposer of the leaf litter that falls into rivers and ponds, and a key prey for fish and amphibians.
• Its larva builds a portable house: a silk tube to which it glues sand grains, shell fragments and little pieces of leaf or stem, and which it drags along with it, with only its head and legs poking out.
• The silk it produces is silky and adhesive under water, and that underwater glue is being investigated in biomedicine as a model for surgical adhesives that work on moist tissues.
• The French artist Hubert Duprat exploited this behaviour: he gave the larvae gold and precious stones instead of sand, and they built their cases from those materials. The resulting works are exhibited in museums.
• The composition of the case depends on what is available, and its shape and weight are tuned to the local current.
• Caddisflies are the sister group of the moths and butterflies, and share with them the ability to produce silk.
• It is a staple in the diet of trout, and many artificial fishing flies imitate its larvae and adults.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Ponds, ditches, canals and backwaters with vegetation and submerged leaf litter

Sexual maturity

The adults from permanent waters emerge at different times and enter ovarian diapause before breeding; those from temporary waters have to emerge early, before their habitat dries out

Gestation / incubation

Laying takes place in late summer in a gelatinous mass near the waterline; the larvae hatch when the mass is wetted or as the jelly liquefies, and the pupa lasts two to three weeks

Litter / clutch size

Gelatinous egg masses laid on vegetation overhanging the water; rain triggers hatching and washes the larvae into the water

Sources consulted: Wiggins, Larvae of the North American Caddisfly Genera · Stewart y Wang (2010), Biomacromolecules · Duprat, obra artística documentada · Wildlife Gardening Forum, ficha Caddisflies · NCBI PMC10318372 · NCBI PMC10318372, genoma de Limnephilus lunatus · guias de biologia de tricopteros · ficha de la familia Limnephilidae · Nature Journeys, ficha Crescent Cinnamon Sedge

Best time: Adults on the wing from May to November, mainly at dusk and at night; they come to light traps