We are now 5 months into our Back from the Brink project here at Limestone’s Living Legacies, and just last week held our very first event - a survey training workshop for volunteers on the Rugged Oil Beetle. This beetle is one of our primary target species, a real rarity, known from only a handful of sites in the Cotswolds and having suffered a dramatic decline over the past 100 years.

It may seem a bit strange to be leading a survey workshop for an invertebrate in the middle of November, but while other invertebrate activity has finished for the year, this particular little beetle is hitting its peak. The Rugged Oil Beetle is one species that is active as an adult from September through to early spring, meaning that autumn and winter is the best time to survey for it. It is, however, also nocturnal - so you do need to wrap up warm when surveying on a cold winter’s night! This didn’t seem to put anyone off - with a turnout of over 30 people to our training workshop, the enthusiasm to learn about and help survey for this little known beetle clearly outweighed the cold and dark!

Before heading out on site we had a great illustrated talk from one of our partners – Buglife, and John Walters, a national beetle expert, who introduced us to the ecology of the Rugged Oil Beetle.
They have an incredible life-cycle which relies on solitary bees. After hatching, the beetle larvae (known as triungulins) make their way onto a flower head where they wait to hitch a ride on the back of a solitary bee. When the bee returns to its underground nest, the triungulins disembark and continue their development underground, eating through the bee’s stores of pollen and nectar. Eventually, the Rugged Oil Beetle emerges as the adult which is what we then set out to look for.

With so many people, we split the group between Swift’s Hill (a Gloucestershire Wildlife Trust nature reserve) and Cranham Common, managed by Natural England. Swift’s Hill has been known as one of the best Rugged Oil Beetle sites in the county for several years, however Cranham Common was found by Natural England to be a new site for the beetle just this year!

Fortunately the weather was kind to us and we managed to see around 20 beetles across the two sites, giving our volunteers a great opportunity to see the beetles up close.
For me, seeing the Rugged Oil Beetles was very exciting, not only because it was a first for me, but knowing how rare they are made me feel very privileged.
We now aim to begin our surveys to get an even better idea of where they are and hopefully see them colonise new areas as we put new habitat management plans in place.


Watch this space…

Jennifer Gilbert

Community Engagement Officer

6 thoughts on “The Rugged Oil Beetle

  1. So pleased enough people care about our fragile environment to help save our plants and creatures that have evolved over thousands of years to fit into their own special place.

  2. Hi Gerry, thanks for getting in touch. I’m afraid I can’t really answer this as I don’t know what the status of the Violet Oil Beetle is or whether this is a species a site could get protection for. You might be able to find this out however from Buglife who are one of our BftB partners. Hopefully they might be able to give you a bit more info. Thanks, Jennifer

    1. Thanks Jennifer. I started ‘managing’ the spot a few years ago (mainly bringing the bramble under control to give saplings a chance and putting pathways through the bramble to give deer easier access.) It’s remarkable how many species are in it at different times of the year. Last year, the onslaught by loggers in Perdredda Wood was quite shocking so it’s besieged now and might be over-ridden this summer or the next. bit.ly/intoper

  3. p.s. to Jennifer: It was too cold for most insects on Wednesday where I found that Violet OB, which leads to the question “What makes these oil beetles so rugged?”

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