Many of the 29 species of robberflies (Asilidae) known to occur in Britain and Ireland show a preference for dry, well-drained soils, coastal dunes being a favoured habitat (Falk et al., 2026). Smith & Kinsella (2020; 2021) recorded and photographed nine asilid taxa on the Sefton dunes in north Merseyside (v.c.59: South Lancashire), suggesting that others might be discovered. In the event, between 2021 and 2025, three more robberflies were recorded in the dune system, bringing the Sefton Coast total to 12. Here, we report on the new discoveries and clarify the changing status of other species.

Species Accounts:

1. Additions

Machimus (Tolmerus) atricapillus Kite-tailed Robberfly

This medium-sized asilid is common in southern Britain, becoming less frequent in the north. It inhabits a variety of open, often sandy, habitats and clearings in woods, often in urban locations (Falk et al., 2026). Our only confirmed record is a female photographed by PK on bramble at Hightown dunes on 17^th August 2024 (Fig. 1). van den Broek & Schulten (2017) pointed out that the female of this species is difficult to identify, with close similarities to other members of the genus. A possible female M. atricapillus was photographed by PHS in Ainsdale Sand Dunes National Nature Reserve (NNR) on 15th August 2017 (Fig. 2). However, the brownish rather than greyish tone of the specimen, together with a short arista and straight ovipositor suggests M. cingulatus rather than M. atricapillus.

Choerades marginatus Golden-haired Robberfly

Characterised by a fringe of golden hairs on the hind margins of the tergites, this medium-sized, nationally scarce robberfly is typically associated with ancient woodland. It is locally distributed in southern England, especially in Hampshire and Surrey, extending north to Merseyside and Lincolnshire. Our only record, the northernmost for Britain, was a male consuming small insect prey, photographed by PK, at Alexandra Park, Crosby, on 2nd July 2024 (Fig. 3).

Neoitamus cyanurus Common Awl Robberfly

A fairly large, slim robberfly, this species has mainly orange tibiae and a broad black stripe down the dorsal surface of the thorax. Females have a long thin ovipositor. It is widespread and frequent in southern Britain, extending to northeast Scotland but scarcer in the north, occurring in both coniferous and broad-leaved woodland. This species has a long flight season from May to October (Falk et al., 2026; van den Broek & Schulten, 2017). New to the Sefton Coast, our only sighting was of a female photographed by PK in Ainsdale NNR on 2^nd June 2025 (Fig. 4).

2. Changing status

Leptarthrus brevirostris Slender-footed Robberfly

A small dark robberfly with a strongly humped thorax and red second and third tibiae; it is patchily distributed and local throughout Britain. Favoured localities include southern chalk districts, Dartmoor, the Peak District, the Lake District and North Wales. A wide range of habitats include chalk and limestone grasslands and, further north, more acidic and woodland conditions (Stubbs & Drake, 2014). Smith & Kinsella (2020) reported the first Sefton Coast sighting in June 2019 in an Ainsdale NNR woodland firebreak. This was seemingly also the first for v.c. 58 and 59. Since then, there have been two further individuals photographed by PK in the same area of the NNR in June 2021 (Fig. 5) and June 2025.

Lasiopogon cinctus Spring Heath Robberfly

Our smallest robberfly, Lasiopogon cinctus (Fig. 6) is patchily distributed in England and Wales, north to Cumbria, in sandy places, including heathland, sandpits and coastal dunes (Falk et al., 2026). Smith & Kinsella (2022) detailed about 12 early records in v.c.59; apart from one in Liverpool, all were found on the Sefton dunes. They undertook a more intensive study of this species during the three years from 2019 to 2021, recording 80 individuals between 12^th April and 1^st June, from Birkdale Green Beach in the north to Crosby Coastal Park in the south, a linear distance of 15.5 km. Observations occurred in seven tetrads and three hectads of the National Grid. Most adults were associated with sandy paths, fences, logs and tree leaves in full sun, sheltered from prevailing winds. The large number of sightings led Smith & Kinsella (2022) to describe the Sefton Coast as a “hot-spot” for this nationally scarce robberfly. The importance of bare sand for the conservation of the species was emphasised. Multiple records of L. cinctus in the Sefton dunes have been added since 2021, larger counts including ten at Ravenmeols on 5^th May 2024, nine at Ainsdale NNR on 4^th April 2025 and six at Hightown dunes on 27^th April 2025. As before, all sightings were made between mid-April and the beginning of June.

Dioctria atricapilla Violet Black-legged Robberfly

This medium-sized, rather plump, mainly black asilid has characteristic dark-blue eyes in the male (Fig. 7). It is a widespread but local species in England, extending as far north as Yorkshire, its favoured habitat being tall grass on a fairly dry or slightly humid soil (van den Broek & Schulten (2017). Smith & Kinsella (2021) described six individuals photographed in tall grass swards at Hightown dunes in June 2020. Numerous records were obtained each year since then at Pinfold Meadow in Ainsdale NNR, Freshfield Dune Heath Nature Reserve, Hawksworth Drive, Formby and Victoria Park, Crosby, the highest count being 17 at Freshfield Dune Heath on 21^st May 2024 (PK). Evidently, D. atricapilla is widely distributed and locally frequent on the Sefton Coast.

Leptogaster cylindrica Slender-striped Robberfly

A delicate robberfly with a long slender abdomen (Fig. 8), Leptogaster cylindrica is said to be common in southern Britain, with records extending northwards to Edinburgh (Falk et al., 2026). It favours a variety of open grassland habitats on reasonably dry soils (Stubbs & Drake, 2014). Brighton (2017) stated that, since the first Lancashire record in 1961, this species had become one of the commonest asilids in the region. However, this was hardly the case on the Sefton Coast, our first not being found until 24^th June 2020 on Ainsdale NNR. Since then, there have been eight additional records, one at Crosby Coastal Park and the rest at Ainsdale NNR, with a maximum count of three.

Machimus (Tolmerus) cingulatus Brown Heath Robberfly

A medium-sized, brownish robberfly, with red-and-black banded tibiae, this species is fairly common but local on sandy areas and calcareous grasslands in southern Britain, with isolated, mainly coastal, records north to Inverness (Falk et al., 2026; Stubbs & Drake, 2014). Smith & Kinsella (2020) mention one earlier record for the Sefton Coast. A putative female photographed by PHS at Ainsdale NNR in August 2017 is cited above (Fig. 2). A further six sightings, confirmed from photographs (Fig. 9), have come from Freshfield Dune Heath in 2021 and 2023, Hawksworth Drive, Formby in 2023 and 2025 and Crosby Coastal Park in 2023. All were during July or August. These observations suggest that M. cingulatus may be fairly widespread along the Sefton Coast.

3. No change

The status of other asilid species recorded on the Sefton Coast by Smith & Kinsella (2020; 2021) seems largely unchanged. Thus, Philonicus albiceps (Dune Robberfly) continues to be frequent throughout the summer on sandy patches and informal footpaths, while Dysmachus trigonus (Fan-bristled Robberfly) remains a familiar sight in similar habitat. Dioctria baumhaueri (Stripe-legged Robberfly) and D. rufipes (Common Red-legged Robberfly) are occasionally photographed along sheltered woodland edges. Smith & Kinsella (2019) reported that Pamponerus germanicus (Pied-winged Robberfly) had been recorded once in 2000 but this characteristic asilid of large dune systems has not been seen subsequently. It might be re-found.       

Based on their national distributions (Falk et al., 2026), other species that could conceivably occur on the Sefton dunes include Dioctria linearis (Small Yellow-legged Robberfly), D. oelandica (Orange-legged Robberfly) and Leptogaster guttiventris (Dark-striped Robberfly). The presence of Machimus cowini (Irish Robberfly) was mentioned by Smith & Kinsella (2020) as a possibility, though unlikely. Brighton (2017) included D. linearis, D. oelandica and L. guttiventris in his detailed check-list for v.c.58 (Cheshire) but not for v.c.59. Interestingly, he lists 14 asilids for v.c.58 but only nine in v.c.59. Our total of 12 taxa for the Sefton Coast represents a sizeable increase of 33% for South Lancashire. Brighton’s (2026) complete checklist of Diptera for Lancashire and Cheshire includes these records and lists 15 species of Asilid for v.c.59.

Acknowledgements:

We are grateful to Mike Wilcox for helpful comments and for proof-reading the manuscript.

References:

Brighton, P. 2017. The Diptera of Lancashire and Cheshire: soldierflies and their allies. Lancashire & Cheshire Entomological Society.

Brighton, P. 2026. The complete Diptera of Lancashire and Cheshire. Lancashire & Cheshire Fauna Society.

Falk, S., Ashton, G., Dimond, R. & Creed, P. 2026. A photographic guide to the flies of Britain & Ireland. Pisces Publications, Newbury.

Smith, P.H. & Kinsella, P. 2020. Robberflies (Asilidae) of the Sefton Coast sand-dunes.                        Tanyptera Trust blog. https://www.northwestinvertebrates.org.uk/robberflies-asilidae-of-the-sefton-coast-sand-dunes/

Smith, P.H. & Kinsella, P. 2021. A revision of the robberflies (Asilidae) of the Sefton Coast sand-dunes. Tanyptera Trust blog. https://www.northwestinvertebrates.org.uk/a-revision-of-the-robberflies-asilidae-of-the-sefton-coast-sand-dunes/

Smith, P.H. & Kinsella, P. 2022. Status of Lasiopogon cinctus (F., 1781) (Spring Heath Robberfly) (Diptera: Asilidae) in the sand-dunes of the Sefton Coast, north Merseyside, UK.  British Journal of Entomology and Natural History 34: 329-335.

Stubbs, A. & Drake, M. 2014. British soldierflies and their allies (second edition). British Entomological and Natural History Society, Newbury.

van den Broek & Schulten, A. 2017. Field guide to the robberflies of the Netherlands and                  Belgium. Stichting, Jeugdbondsuitgeveri.