Sefton Coast Wildlife

Roesel's Bush Cricket

Roeseliana roeselii

UK Green ListModerate📍 Ainsdale NNR
Season
July–October.
Best time of day
Males sing throughout warm days — continuous, insect-like buzz
Sefton Coast
Established on the Sefton Coast; now regular in tall rough dune grassland
UK population
Expanding rapidly northward; now well-established in Lancashire

Tap image to enlarge · Wikimedia Commons

Overview

Roesel's Bush Cricket has been expanding northward at an extraordinary rate, reaching the Sefton Coast in recent decades. The male's song is one of the most distinctive insect sounds: a continuous, electrical buzzing that sounds more like overhead power cables than a cricket. On a warm summer day in the tall grass at Ainsdale, this constant buzz is increasingly a background sound. The distinctive pale yellow-green border around the pronotum is the key identification feature.

At a Glance

OrderOrthoptera
FamilyTettigoniidae
HabitatTall dune grassland · Rough coastal grassland · Scrub edge
DietGrasses, vegetation, small invertebrates
UK populationExpanding rapidly northward; now well-established in Lancashire
Sefton CoastEstablished on the Sefton Coast; now regular in tall rough dune grassland
ConservationUK Green List

Where to See It

Tall rough grassland at Ainsdale NNR and coastal scrub edges. Expanding northward rapidly.

Identification

Medium bush cricket. Green-brown with distinctive pale yellow-green border around the pronotum (thorax shield). Long antennae. Partially winged — most individuals short-winged, but occasional fully-winged individuals occur. Continuous electrical buzzing song.

Viewing & Photography Tips

Walk tall rough grassland at Ainsdale in August. Listen for the continuous electrical buzzing — once you know it, you'll hear it everywhere. The pale border around the thorax is the key feature.

Conservation Status

UK Green List

This species has a favourable conservation status in the UK and remains an important part of Sefton Coast biodiversity.

Frequently Asked Questions

Why has Roesel's Bush Cricket expanded so rapidly northward?

Roesel's Bush Cricket has expanded its UK range northward by several hundred kilometres since the 1990s, linked to warmer summers. The species needs sufficient warm days to complete its life cycle, and climate warming has extended its viable range. Climate warming has now made Lancashire summers warm enough for breeding populations to establish. This is one of the most dramatic documented range expansions of any British insect.

Related Species

Plan your visit to the Sefton Coast

Marshside RSPB, Formby pinewoods, Ainsdale NNR — practical guides to getting there, what to bring, and the best spots for each season.