Two common ground beetles

We came across two Ground Beetles, and they happen to be two of the commonest species in the UK. The top shot is the Strawberry Seed Beetle, Harpalus rufipes, a female. The elytra of this species look duller than the thorax, as they are covered with fine hairs, which you can see glowing in the photo below of the same individual, as they glistened with the flash light. They eat many vegetable matter, and appear to be partial to ripe strawberries.

The next species, larger (15-20 mm), is the Black Clock beetle, Pterostichus madidus, a very shiny, large headed species with impressive jaws and eyes. They are mainly predatory, and feed on ground invertebrates. This individual is a male, recognised by the enlarged tarsi of the forelegs.

There are many species of ground beetles (about 370) and many are hard to identify. These are some websites that might help you ID them:

Mark Telfer's website

Mike's Insect keys

Ground beetles of Ireland

Watford Coleoptera Group

Let me know if you know any others!

A Strawberry Seed Beetle

Given that the weather is so damp and cold I am seeing very few insects these days other than bumblebees. At least I have plenty of time to tidy up my ever growing photo library! While going through my ground beetle photos, I thought I would share this shot of  Harpalus rufipes, a common species that I have even found inside the house. The species is quite distinctive with its orange legs and its wings covered on very fine hairs - giving the elythra a matt feel when compared with head and front of the thorax. This is an omnivorous beetle: it will predate small invertebrates but also feeds on seeds, and gets its English name from the damage it inflicts on strawberries. The species is biennial. It breeds in August and the adults overwinter and overlap with the larvae. The larvae dig deep vertical where they cache seeds, which I thought it is pretty cool behaviour for a beetle. As other common European invertebrates, it was introduced in North America before 1937.

More information

Loughridge, A., & Luff, M. (1983). Aphid Predation by Harpalus rufipes (Degeer) (Coleoptera: Carabidae) in the Laboratory and Field. The Journal of Applied Ecology, 20 (2) DOI: 10.2307/2403519


Hartke, A., Drummond, F., & Liebman, M. (1998). Seed Feeding, Seed Caching, and Burrowing Behaviors of Harpalus rufipes De Geer Larvae (Coleoptera: Carabidae) in the Maine Potato Agroecosystem. Biological Control, 13 (2), 91-100 DOI: 10.1006/bcon.1998.0645

Never hold a Black Clock in your mouth

I found a squished ground beetle on the pavement today, Pterostichus madidus, and I thought I would share with you some photos from last year of a very alive individual of this species . Curiously this carabid beetle has a curious English common name: the Black Clock. According to the book Bugs Britannica, by Marren and Mabey 'clock' was a word in widespread use to mean any big buzzing insect. As many carabids, however, this is a fast, non-flying nocturnal predatory beetle which runs to hide quickly when uncovered. This one was found under a grass tussock in the garden. Look at his sharp jaws!
 Ground beetles have glands at the end of the abdomen that produce defensive, foul tasting and caustic secretions. I must quote here an incident involving ground beetles described by Charles Darwin

I must tell you what happened to me on the banks of the Cam in my early entomological days; under a piece of bark I found two carabi (I forget which) & caught one in each hand, when lo & behold I saw a sacred Panagæus crux major; I could not bear to give up either of my Carabi, & to lose Panagæus was out of the question, so that in despair I gently seized one of the carabi between my teeth, when to my unspeakable disgust & pain the little inconsiderate beast squirted his acid down my throat & I lost both Carabi & Panagæus!

The pains beetle collectors went through to capture priced ground beetles! You can admire the handsome Crucifix Ground Beetle (Panagaeus cruxmajor), also known as 'Darwin's lost beetle' here. Unfortunately, due to collecting and habitat degradation, this species, formerly widespread, is now just know from three populations in the UK.
But back to my beetle, I managed to take some shots of the individual scurrying off for cover on the soil, and then I decided to capture it and give it a session in the white bowl. I think the following two photos show the pros and cons of the natural versus the white background.

Pterostichus madidus, 12 May 2012

More information

Charles Darwin letter to Leonard Jenyns in the Darwin Correspondence project.

Crucifix ground beetle (Panagaeus cruxmajor) UKBAP plan.