Pimpla hypochondriaca

by Richard Jones

...suddenly something caught my eye - a dark flitting creature an inch long, with bright red legs and a menacing pointed tail.

Pimpla hypochondriacaThe fabulous fine weather of Sunday saw me in the garden trimming back a rose bush that was reaching threateningly across the path at head height. Suddenly something other than a branch of thorns caught my eye - a dark flitting creature an inch long, with bright red legs and a menacing pointed tail. It could only be one thing: the spectacularly intimidating, yet bizarrely and intriguingly named Pimpla hypochondriaca.

If there were any insect that deserved to have an extraordinary English name given to it, then this is the creature. But, sadly, it is just 'one of the ichneumons', which is quite frankly pathetic. Ichneumons are large and striking insects, allied to bees, wasps and ants. (Ichneumon is also another name for the Egyptian mongoose but we don't get those in East Dulwich). All ichneumons are parasitic, laying their eggs in a wide range of insects, but especially moth and butterfly caterpillars. The venom injected at the same time contains an immunosuppressant, preventing the immune system of the host insect from fighting back. The eggs hatch and the ichneumon grubs then eat the insect alive, from the inside. Although they are amongst the most important of biological control agents, they are incredibly poorly studied; the few identification guides are highly technical and the nomenclature is constantly being revised. Despite their large size, bright colours and fascinating life histories, most entomologists ignore them.

This is one of our largest and most easily identified. There is nothing else quite like it. And it's very common, occurring throughout the country in parks, gardens, meadows, woods and forests. It parasitizes a huge range of moth caterpillars, including common garden species like yellow underwing, Noctua pronuba, and lime hawkmoth, Mimas tiliae. It is not even put off by the stiff hairs and silk web nests of browntails, Euproctis chrysorrhoea, which is where I photographed this one a few years ago. The one on the roses was much too quick and had vanished before I could even remember where I'd put the camera.

I'm still left guessing how it got its peculiar scientific name. In medicine, hypochondria is apparently derived from the Greek, hypo meaning 'below' and chondros, the cartilage of the breast bone. According to the ancients, this part of the abdomen, containing such mysterious organs as the liver, spleen and gall bladder, was the home of melancholy and other emotions concerned with worry, fear and phobia. Quite what Anders Jahan Retzius, the Swedish chemist, botanist and entomologist who first named the insect in 1783, was thinking, perhaps we'll never know.

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Gardeners' World Web User 03/10/2008 at 02:53

I saw one of these the other day just outside my doctors in barrow cumbria, i got the shock of my life it looked so scarey! red legs and a long sting, anyway thats how ive come to be searching it, I didnt know the name of it,i just searched insect with long sting red legs, when i saw it fly towards us and land on a window i thought it looked terrifying, i grabbed my little girl and ran off !! "saying thats not from round here"!!

Gardeners' World Web User 04/10/2008 at 22:36

I found one of these this year and last year in my garden. I also found (last year) a parasitised? large white caterpillar having climbed up my window with the maggots of the Ichneumon wasp emerging. unpleasant it may be but live and let live is my motto we need all the wildlife we can get. The great lack of butterflies this year can be blamed on the weather, and not on this wasp it can help itself to one or two caterpillars. I find insects quite fascinating.

Gardeners' World Web User 10/10/2008 at 19:56

Am I the only one here who think these wee beasties are the most amazing creatures? They may have some horrible habits which seem like something from a scary science fiction film but they are very impressive to look at.

Gardeners' World Web User 19/07/2009 at 06:52

We live in Normandy, France and my husband found an insect just like this, Pimpla hypochondriaca,inside his slipper! I think his big toe knocked off a wing and the poor thing couldn't fly away, but it gave us the chance to get a closer look. A little scary but harmless I believe? We put it back outside hoping it could grow another wing, would it? SC

Gardeners' World Web User 29/09/2009 at 16:35

I usually don’t post on Blogs but ya forced me to, great info.. excellent! … I'll add a backlink and bookmark your site.

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