Burying Beetles

I smiled when I saw Chris Packham getting excited about a beetle on tonight’s episode of Springwatch. It was not just any old beetle, but a colourful Sexton Beetle (Nicrophorus vespilloides), sometimes known as the burying beetle. I photographed this Sexton Beetle at work one summer and am grateful to the camp site manager for bringing it to my attention when he found it crawling on his jacket – despite him disliking bugs.

Sexton Beetle - Nicrophorus vespilloides

Like Chris, I too, think it is a fascinating beetle.

I put this beetle in a bug viewer for a few minutes as I reached for my Field Guide to ID it and it went crazy! It hurtled round and round at high speed and there was no way of getting a picture when in there. It seemed to be really annoyed by the mites which were crawling all over it. I just had time for one quick picture when I tipped it out of the container.

The Sexton Beetle or Burying Beetle get its name from the fact that the adults bury the corpses of small mammals and birds to feed their larvae. They fly well and are said to be able to scent a dead body up to two miles away. When the the burial is complete – a process which can take up to 8 hours – the adults strip off the fur or feathers. As they do this they coat the carcass with secretions which slow the decay processes and prevent the odour from attracting other animals. The female then lays the eggs in the soil nearby where they hatch after a few days. The larvae are able to feed on their own, but to speed their development the parents digest the flesh and regurgitate the liquidised food. If there are too many larvae for the size of the carcass the parents may reduce the number to suit.

These beetles are frequently infested by tiny reddish-brown gamasid mites (Gamasus species), like in the picture above. These mites cluster between the body segments, under the wing-cases and anywhere else that the beetle cannot easily reach with its legs to dislodge them.

I found the beetle fascinating, but, for some reason, felt a bit ‘queasy’ about the mites. Although the beetle appeared to be troubled by the mites this is a mutually beneficial arrangement.

The mites use the Sexton Beetle to travel from location to location, a phenomenon known as phoresy, in order to take advantage of flight to access a new food source. The Mites feed on carrion fly eggs and maggots, so phoresy is mutually advantageous to the Mites and the Burying Beetles. The Mites get a food source and the Burying Beetle benefits because more rotting flesh is available to its young.

I have seen other Sexton Beetles at the camp site since this one, and some were so heavily infested with mites it was a wonder they could fly at all.

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7 comments on “Burying Beetles

  1. I don’t blame them – I wouldn’t like the mites, either!
    I don’t particularly care for bugs generally, but I don’t mind beetles. I used to play with large ones called “June bugs” when I was a child. I can’t stand roaches, though — *shudder*!

  2. Fascinating! What an effort these wee guys go to to bury a carcass, and prevent it being found by other scavengers. The relationship between mite and beetle is equally interesting – it boggles my mind to think about how these complex relationships came to be…

  3. Fascinating stuff and a great image of a really striking insect. I’d never really considered the possibility that insects might host other insects as parasites. (And yes – those mites are a bit unsettling!)

  4. Oh my god thank you for posting this! .. ive been trying to find out what kind of beetle this was and what the heck was on its back. .. i was outside having a smoke and one just flew right into my face then landed on my sleeve. my boyfriend ended up catching it in a bottle. when i went to take a closer look to see what was moving on its back when it landed i seen at least 10 tiny whitesh-orangesh bugs crawling all over. i was discusted!! lol

  5. One of these beetles appeared in my living room floor one day. I had never seen one before and had no idea what it was. Very large and scary looking but also very beautiful. Less scary when covered in a glass! Much happier when I found out what it was. I saw another in the garden a month or so later. A great opertunity to look at a large beetle. Not a common sight in Fife I can assure you.

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