How to Survey for the rare Caddisfly Anabolia brevipennis – Watch Our New Video!

2025 December 19 by Tanyptera Project

Anabolia brevipennis is a Nationally Rare and Vulnerable UK caddisfly. Its distribution is restricted, with most records concentrated in north-west England, where it is typically found in pools within Fen Carr Woodland. There are only occasional historical sightings elsewhere. Narrow habitat requirements and a cryptic nature mean the species can easily be overlooked without targeted search efforts, even at known extant sites. However, with the right knowledge and some persistence, it’s possible to detect and identify the mature larvae in the field due to it’s characteristic triangular case. With the ability to survey for A. brevipennis, new populations may be found, and those already known can be monitored to inform conservation management.

We hope the guidance in our new video and summary information below will be useful for landowners and site managers of Fen Carr Woodland, as well as those keen to help record this species.

✅ Where to Look

Shallow pools in Fen Carr Woodland, often with dead leaf fragments and a slight water flow.
These pools typically dry up in summer, so timing matters.
Please remember to get landowner permission when surveying a site and be careful around water.

✅ When to Survey

Larvae: Late winter through to spring (April is ideal)
Adults: August – October. They emerge before the pools dry up. Very secretive – presumed to hide amongst dense vegetation and wood debris at the breeding site.

✅ What to Look For

Larval cases: Triangular in cross-section, made from dead leaves. These cases can persist even after pools dry up.
Larval signs: Circular cut-outs on dead leaves.
Adults may come to light traps on site, but resemble common species, so identification from larvae or larval signs is preferred / easiest.

✅ Record your Findings