A recent morning spent searching for insects led me to realise how much of my job requires me to peer into the distance looking for large things far away. On hands and knees, inspecting flowerheads in minute detail was an odd feeling, with my eyes taking time to get accustomed to the close focal distances involved.

The reason for my unusual position was a visit from Buglife International Conservation Officer, Andrew Whitehouse, on the search for one of the strangest animals to be found locally. Buglife are in the midst of a project to gather information about the UK distribution of oil beetles and the EDDC Local Nature Reserve at Seaton Marshes is of particular interest for these insects.

For some reason, the flood defence bank constructed in the 1960s, is now a major site for oil beetle sightings in spring. By March each year, on warm sunny days, huge rotund glossy black beetles can be seen hauling their engorged abdomens through the grass in search of a mate and the beginning of a peculiar life cycle we had come to find the next stage of.

Hundreds of thousands of eggs are laid by the females in early spring, in open, sandy soil intended to provide a warm incubation for the developing eggs. In a matter of weeks, the eggs hatch tiny larvae, which look totally unlike the adult beetles. These larvae are known as triungulins and their hook-like clawed feet are adapted for hitching an amazing lift to the next stage of their life. They crawl about over the flood bank, climbing up any tall object in the grass, looking for flowers from which to thumb a lift. They position themselves in the corolla of the flower and wait for a bee to visit the flower, when one arrives, on they hop for a lift to the bee’s burrow.

The bee takes the interloper into its underground nest, whereupon the triungulin drops off the bee and proceeds to feed on the bee’s eggs and grubs before munching its way through the stores of wax and pollen. This protein feast fuels the triungulin’s development through the summer before it pupates in the burrow and waits through winter before the first pale spring sunshine bring them above ground to start the process over again.

The thing which makes Seaton Marshes so interesting to Andrew and his colleagues at Buglife is the fact that the oil beetles are only found on the flood defence bank, a man-made structure which was not intended to be a haven for insects.

The adult oil beetles do not move a huge distance from the bee’s burrow in the spring, so as well as the flood bank being an oil beetle bank, it must be a pretty good bee bank too. Although, having said that, we failed to find many bees on Wednesday’s foray.

We did, however, find a few of the larvae and, this being the first time I have discovered these things, I was leaping about like a five year old! I’ve seen photographs of violet oil beetle triungulins swarming over buttercup flowers like tiny black thrips.

However, the black oil beetle larvae found on Seaton Marshes are vivid orange in colour, so were a much harder prospect to find against the butter-yellow flowers.

Andrew found two almost instantly, and so I got my first encounter with an oil beetle larva. It was so small my eyes watered to focus on it, and I needed to lie down in the grass to get close enough to see it with any clarity; it must be my age catching up with me!

First ones found, I was determined to spot one myself, but it was a good 30 minutes later, during which time Andrew had found about 200 further larvae, before I finally spotted one for myself! They were incredibly active little creatures, and some of the plants were festooned with the bugs. It was also interesting to note that they were not fussy in what they latched on to either, with the two sailor beetles in the photo, carrying a heavy load of the things. They can be seen in the picture on the lead beetle, looking a bit like a ginger mane behind its head.

More study will have to take place on the marshes to discover exactly why this bank is such a hit with the bees and the oil beetles before we can draw conclusions as to the function they play.

Is it the secondary bank which provides shelter to the southerly facing embankment which makes the difference, or the very light grazing provided by the cattle?

When we can make assumptions about why this small section of the nature reserve is such a haven for bugs it will help in the design of bug banks, and other new constructions which aspire to have an ecological function as well as an engineered purpose.

Fitting wildlife into our buildings, towns and cities is an increasingly important role for conservation to assist with, and it is fortuitous accidents like this one which we can learn so much from in our quest to make East Devon as wildlife-rich as it possibly can be.