Short-necked oil beetle

Meloe brevicollis

Key facts

Gaelic name: daolagan-ola geàrr-mhuinealach
Scottish distribution: Coll, Tiree, Islay, Barra and Uist
Length: Up to 24mm
Status: IUCN – Vulnerable, Nationally Rare in Great Britain
Species on the Edge areas: Outer Hebrides; Argyll and Inner Hebrides

Species information

How to identify

The short-necked oil beetle is a shiny blue-black beetle which grows up to 24mm in length. It has a rectangular thorax (wider than it is long). Its antennae are short, straight and thickened towards the tips. They have large abdomens which protrude from under short elytra (wing case) – they are sometimes described as looking like they are wearing a waistcoat that is too small for them.

Lifecycle

Oil beetles have one of the most extraordinary life cycles of any British insect – they are nest parasites of solitary mining bees. Females dig a short burrow into which they lay up to a thousand eggs. For short-necked oil beetles, these eggs develop and hatch quickly, emerging later in the same season. Once these hatch the larvae (triungulins) climb to the top of the nearest flower and wait for a bee to arrive. They then grab onto the bee and hitch a lift back to its nest; the triungulin will then consume the pollen stores and either the egg or larvae of the bee. The triungulin will then stay in the bee’s nest, where it will pupate and emerge as an adult oil beetle when conditions are right the next spring.

Distribution

In Scotland, short-necked oil beetles have been found on the Isle of Coll, Tiree, Islay, Barra and Uist. The Tiree, Barra and Islay populations were discovered during the Species on the Edge programme.

They are known from two locations in South Devon and South Wiltshire in England, and one location in South Pembrokeshire, Wales.

Habitat and feeding

Habitat: Flower-rich coastal grassland and sand dune habitat – especially machair grassland.

Feeding: Adults feed on petals and leaves of flowering plants. Larvae feed on stores in solitary bee nest burrows.

When to see

They can be seen from March to early July.

Conservation status

IUCN – Vulnerable, Nationally Rare in Great Britain

Threats

Short-necked oil beetles are threatened by loss of suitable flower-rich habitat due to climate change, coastal development and changes to grazing. They are particularly vulnerable due to their small, scattered populations.

What Species on the Edge is doing

Monitoring and surveying to find new populations and better understand the species’s needs.
Working with landowners to undertake small habitat management interventions.

How you can help

You can support short-necked oil beetles by helping us learn more about the species. We are looking for volunteers to help search for short-necked oil beetles in likely locations in the Hebrides from April to June. If you want to help us search search for this amazing beetle in sand dunes and machair grassland near you, please contact scotland@buglife.org.uk. All training and support are provided, and no experience is necessary.

You can also help by joining the Scottish Oil Beetle Hunt citizen science survey. No prior knowledge is needed to take part; anyone and everyone is encouraged to submit your oil beetle records using the iRecord app (with multiple photos if possible), or to send in details via email: scotland@buglife.org.uk. Let us know what you find using #OilBeetleHunt on social media!

Explore our work for the short-necked oil beetle

Short-necked oil beetle on a finger — Rare beetle found at Species on the Edge Outer Hebrides launch event

24 short-necked oil beetles were found at the Species on the Edge launch event in the Outer Hebrides.

Resources

If you are interested in learning more about our work for the short-necked oil beetle and how you can get involved, get in touch with your local Species on the Edge team.