About 3 o'clock last Sunday morning, I was rudely awoken by being stung on the inside of my right forearm! Swearing loudly (I do find it helps in such situations; hopefully not loudly enough for my next-door neighbours to hear!), I quickly flicked on the bedside light, expecting to find a social wasp and keen to deal with it before it could sting me again. I found it was actually an ichneumonid, which rapidly left my forearm and flew off to hide. I didn't think these could sting!
My arm grew a red, burning, stinging lump the size of a pound coin before my eyes. I couldn't see where the wasp had gone, and my throbbing arm disrupted my sleep for a couple of hours, until the antihistamine and Tiger Balm kicked in, reducing the unpleasant effects. I slept in late; the cats sensed something was up, and were very cuddly and purry, one on either side of me, comforting and protecting.
Ichneumonids are parasitic wasps (or more accurately, parasitoid, as they kill their hosts). They come to light and are often a nuisance while moth recording. I've also seen some of the day-flying ones in the garden, and was meaning to look them up, even if only to roughly genus level. There are apparently around 2500 species in the UK and they can be really difficult to separate, even with a microscope.
I looked up whether stings from the likely suspects (genera Ophion and Netelia) were known and there seemed to be some divided opinion on wildlife and gardening discussion groups. A few people said they'd been stung, and a number of other people replied that ichneumonids don't sting. Some sources state that the females can and do use their ovipositors as a sting in defence, although they don't have the poison sacs that social wasps have. Others have had Ophion sting them without provocation and noted that it was quite painful and caused inflammation, more than they'd expect from a quick jab. It seems reasonable to think that they can inject some sort of irritant, as they immobilise their intended host with it. Perhaps I'd trapped her under my forearm. Either that, or I smell like a caterpillar and she tried to lay an egg .... Ugh!
By Sunday night, the red bump was 3 cm in diameter and intensely itchy. As soon as I switched on the bedroom light, the wasp flew out from the lampshade. Considering how chaotic the house is, I was amazed I could find my bug box easily. The wasp was also easy to catch.
Monday, very grey daylight (call this summer? I'm in long sleeves and not impressed!); armed with the Natural History Museum's Beginners Guide to Identifying British Ichneumonids, I sat down to take a closer look at the offending insect.
 |
| The offending insect - Ophion luteus or similar |
Satisfied that I wouldn't get any closer than that, and noticing that the red bump was now in the centre of an inflamed area 7 cm in diameter, I emptied the bug box unceremoniously out of the bedroom window.
With a loud 'snick', a sparrow who'd been perching in the privet flew out and caught the wasp as she started to fly away. It felt like a sort of natural justice had been done.
Postscript: A week later, the swelling and inflammation has gone down, although there is still a pink bump. There has been one of these in the bedroom every night except last night, when there was an Ophion minutus or similar specie and then two of the larger ones. I got very fed up of catching and ejecting them, so last night I took a fly swat to the Ophion luteus (?). The first one took some beating; so I took the head off the second one and even then, it kept curling its body as if trying to 'sting' the fly swat.
No more Ms Insect-Tolerant Nice Lady as far as these are concerned.
2 comments:
Looking at the photo, I can see there's no ovipositor and I think maybe she left it in your arm and that would definitely explain things. Ouch!
Ophion luteus only has a short ovipositor (unlike some other genera which have great long things!) which can't be seen from the dorsal view. I read somewhere that they inject something to subdue their host caterpillar, so presumably that was responsible for the inflammation.
Post a Comment