I recently accepted the task of producing an image per month with which to demonstrate the hidden wonders of Seaton Marshes in order to promote the area and encourage people to look more closely at the site. I immediately set about attempting to take numerous shots of the visiting waders to the estuary, I previously had not spent much time at the hides and so was able to make the excuse to do so. I found that getting the image I wanted was going to be quite a task and so following another disappointing session I wandered dejectedly back along the path to see if I might find the elusive Otters at Borrow pit, that all and sundry seemed to have observed other than me!
Staring at the ground to ensure my footing, my eye was caught by a flash of dark black against the somewhat bland light green bank - a Beetle. This would need my Macro lens, so kit dumped to the ground, lens changed, I was now in my element. I set about taking a series of shots of this fantastic beetle.
Now happier I moved on only to find more examples of this beetle, many of them in a mating frenzy. A full head count revealed 41 specimens, I later ratified this with another 2 counts with my children on visits over the next 2 days - see previous blog. What I did not know at the time was that I had stumbled across an Oil Beetle which due to severe decline in numbers are fairly rare. Oil beetles are from family of beetles that share a fascinating life-cycle in which the larvae are nest parasites of certain bees . This species, Meloe proscarabeus is bluish black in colour with a long swollen abdomen, which is particularly pronounced in females when they are producing eggs. Females are usually much bigger than males as can be seen above.
Only four of the nine oil beetle species native to Britain remain, and the number of locations where these species can be found has declined drastically. They were once common, but are now limited in their distribution and abundance. South West England is a stronghold but even here their numbers are in decline. Oil beetles have an amazing life-cycle. The larvae are parasites of the ground-nesting solitary bee. They emerge in early spring as adults and begin the job of mating. The females dig burrows in the ground , into which they lay batches of 100's eggs, ( a single female can lay 1000 eggs). The eggs then hatch and the beetle larvae (known as tringulins due to the 3 claws at the end of their legs which enable them to climb) climb up onto flowers where they wait for a host bee. They attach themselves to the bee whilst it collects nectar they will then be flown to the host’s burrow, where the tringulin turns into a grub-like larva, and develops by feeding upon the pollen stores and eggs of the host. The larva will then pupate and the resulting adult beetle will spend the winter inside the host’s burrow before emerging the following spring to start the cycle again
Buglife, the Invertebrate Conservation Trust, is currently running the Oil Beetle Conservation Project, which aims to establish the current range of Britain’s remaining oil beetles and to carry out research into their life-cycles and ecology in order to guide conservation actions targeted at these beetles.
For more on the Buglife Oil Beetle Project and for details of how to help see: