More lesser stag beetles

My kids found two live Lesser Stag Beetles on the pavement near the tree stump, now covered on flowers, where they grow. I couldn't resist the photo opportunity. As they often get squished, we took them home for release in our log pile after a few photos. This year we have found 4 females (2 live, 2 squished) and this male. They are my favourite beetle, the males are so powerful looking but still they have nice large smiling eyes. If I tickled him on the head with a small stick, he raised the front of his body and opened his jaws wide (above), awesome!

Male on relaxed position.

Dorsal view

 Female (left) and male (right). This is one photo in which I positioned both individuals opposite each other. Note the differently sized head and mandibles, despite similar length. The surfacing of thorax and head are also different in both sexes, in the male they look matt, while in the female they are punctated and shiny. Both sexes dig soft, rotting wood with their legs. The male still had some wood stuck to his legs.

This view shows the 'tooth' on the jaws.

For more posts on Lesser Stag beetles on BugBlog click here.

Tree sculptures and lesser stag beetles

In the last three weeks, I have been coming across Lesser Stag Beetles (Dorcus parallelipipedus) dead on the pavements in my street. June and July are peak emergence time for these dark, flattened beetles. Today we found 10 squished ones and a live one next to a chestnut tree stump, is this were they were coming from? I got the impression that the beetles might have been seeking shelter under the wheels of a car parked next to the stump, and they were inadvertently squashed every time the car moved. This tree stump used to be a tree sculpture (here for a photo, yes, the car behind is the beetle squasher!). Old trees that have got too big are partially felled in our neighborhood to avoid subsidence and then carved into statues. The dry dead wood soon becomes peppered with many tiny beetle holes, which are taken over by little wasps to nest, accompanied by their suit of parasitoids. The sculpture was taken down last year as it had started to rot and become unstable. The remaining stump was as soft as crumble. When I looked into it today, many large exit holes were visible on the surface. I dug a bit into the rotting wood with a stick and it didn't take long to find a Lesser Stag Beetle larvae. They have a large head, strong dark mandibles to chew the rotting wood and a c-shaped body curled underneath. The larva was very active, it turned round and quickly moved away hiding into the wood. Millipedes, woodlice and earthworms shared the dead wood with the beetle larva.

The collection of dead Lesser stag Beetles. The one on the bottom left-hand side is a large male with impressive jaws. There is huge variation in size amongst individuals.

A close up of the stump with exit holes.

An overview of the Chestnut tree stump

A side view of the young larva

Lesser Stag Beetle larvae take over two years to develop, and several stages may coexist in the same stump. Adults also may live several years, so it is a shame so many are dead, but this stump probably holds many tens of larvae and many adults have probably already dispersed successfully after emergence. 

Sexing Lesser Stag Beetles

There appears to be a healthy Lesser Stag beetle population in the neighbourhood. Only in my street, I have come across at least six individuals (unfortunately, two of them had been squished on the pavement) in four years. So far, however, I had only seen females, and I was pleased to find a fierce-looking male this morning. This species is often mistaken with Stag Beetles. But Lesser stag beetles are smaller and uniformly black-grey with fine puntuated bodies. They have strong legs with teeth which they use for digging, especially the females, and, when disturbed, they crouch and retract their legs and antennae under their bodies. Although they are not as easy to sex as the Stag Beetle, males and female Lesser Stat Beetles can be told apart based on several features. First, males have larger mandibles, with a rounded knob on them. Females have two characteristic small bumps on their forehead, between their eyes. The third one is that male heads are wider, almost as wide as their thorax, and therefore their mandibles are also set wider apart. Based on the photos and info I've seen, it appears to be a lot of variation on body size (from 20 to 32 mm) and in knob size in males.

Male

Female

For lots of information about the life cycle of the Lesser Stag Beetle and relatives visit Maria Fremlin's website.

National Insect Week Gallery

I have been too busy writing down stuff I've been watching or compiling records, and generally watching bugs these last warm days to blog, but I have decided to put an end to this by celebrating National Insect Week (21-27 June) with a gallery of the bugs I have been watching. I hope you enjoy them.

Flies: This is a large hoverfly, Vollucella pellucens. I have been watching them today hovering and I tried in vain to get a good shot in flight. This one posed nicely for me though.

 Bees: I had a great time watching Anthophora furcata in my local wildlife garden. This female is gathering pollen from Stachys sylvatica.

 Butterflies: the first ringlet of the year. It was warm and this individual fluttered for quite a while before settling on the grass.

Moths: yesterday I spotted this Narrow Five Spot Burnet atop a Knapweed seed head.

And more bees: After cutting a piece of Circaea luthetiana, this female Leaf-Cutter Bee (most likely Megachile centuncularis) had to retreat and alight again as it couldn't fight the wind carrying the piece of leaf. After a while, it flew away to her nest.

A sunbathing Wool Carder Bee (Anthidium manicatum) female.

Beetles: A female Lesser Stag Beetle walking over some plants on a front garden yesterday. So far, I have only seen females in Hull.

More bees: A Bombus hortorum extends its long tongue before landing in a Digitalis lutea flower. This is the longest-tongued bumblebee in the UK.

A male Colletes daviesanus resting on an Oxeye Daisy flower and...

a female with loaded pollen baskets nearby.

To end, another bee (of couse) a female Anthidium manicatum feeds on a Geranium flower on the summer solstice.

A lesser stag beetle

Other than ladybirds, the occasional carabid or a few weevils, beetles do not figure very high on the list of common garden visitors. I was so pleasantly surprised when on Sunday, while tidying up the garden we came across a Lesser Stag Beetle (Dorcus parellelipipedus). These large, grey-black beetles, related to the Stag Beetle, are not uncommon in the UK, but sightings are rare north of the Humber according to the National Biodiversity Network Gateway. The adults and larvae feed on decaying wood - particularly ash, apple and beech. This is the second one I see in Hull. We live in a street lined with large trees and I collect dead fallen branches - including those from a large ash - from the verges and bring them to our garden for our log pile (we also used those for our bee posts). The log pile (see this for an interesting page on log piles) tends to be full of common critters like snails, woodlice and earthworms, nothing very exciting. Occasionally Digger Wasps nest in the decaying wood and I would like to think this beetle was actually born in the garden.