[An Archaeologist’s Guide to British Species] #79: Caddis Fly

In 2023, I am continuing to blog an A-Z compendium of human interactions with species in the British landscape. A list of references for information used in this series can be found here. An index of species covered so far can be found here.

Trichoptera (Sericostomatidae) cases from an archaeological site at Leatherhead, Surrey, UK. Photo by Matthew Law (CC BY-SA 4.0)

Caddis Fly

There are around 190 species of caddis fly or Trichoptera in these islands. They are mostly nocturnal and resemble brownish moths. The larvae, which live in water, make tubes out of sand or bits of vegetation camouflaged with pieces of shell and stone. This trait gives the caddis fly its name – caddis man was a name for a pedlar who travelled the countryside with his clothes decorated with his wares. 

Caddis fly larvae are preyed upon by fish, and some species are popular bait used by anglers. Their cases are sometimes preserved in archaeological sites, where they may be indicators of the presence of standing or flowing water