Monday, January 16, 2012

Convolvulus hawk-moth (deceased)


I receive quite a lot of natural history specimens to identify, some live, some dead. I found this dead Convolvulus hawk-moth Agrius convolvuli specimen waiting for me when I went into work last week. It was in a plastic beer glass, covered in cling-film .......although it must have been deceased for some time ..... with new indication of who left it or where it was found, but I'm assuming it was local i.e. from Durham.

Even in death it's a magnificent insect and when it was alive and hovering in front of flowers it must have been truly spectacular. Those wings are each 4 inches long, making this one of the the largest British moths on a wing-span basis. Convolvulus hawk-moths migrate here from North Africa in late summer and this one must have benefited from the long, mild autumn before it expired.

The natural distribution of the species extends into tropical East Africa and right across Asia. There are records in the literature of it pollinating papaya and baobab trees in Kenya. Those that reach here, after a 1000+ mile migration journey, tend to feed on nectar from flowers of night-scented flowers like tobacco  and the caterpillars, which don't survive the winter here, feed on Convolvulus spp. leaves.



The proboscis of a convolvulus hawk-moth is something to behold. In his New Naturalist book Moths E.B. Ford (1955) mentioned that it can be three times the length of the body when fully extended. When this one died the proboscis contracted into a tight, brittle coil that I can't uncurl, to test the veracity of Ford's claim, but you can see here the slot between the eyes, on the underside of the head, where the proboscis normally sits.

In the newer New Naturalist book on moths by Mike Majerus (2002), he mentions that each compound eye of one of these moths has 27,000 facets. Hawk-moths certainly have outstanding low-light vision and can easily locate flowers by moonlight as well as by scent. There is evidence in the literature of some hawk-moths locating flowers by starlight on moon-less nights.

Convolvulus hawk-moths tend to spread up through Europe on their migration flights. reaching as far north as Norway in some years. It seems that the few that reach England cross the English Channel and most often turn up in the southern counties but Majerus also mentions that they regularly take refuge on North Sea oil rigs, so maybe these head north into Scandinavia then cross to eastern England via a North Sea route?

A magnificient moth ..... so thanks to whoever it was who left it for me to have a look at. Now I want to see a live  one and will be planting tobacco plants and lurking with a torch in late summer - ever the optimist!

5 comments:

  1. What an amazing creature - wings four inches long! I do hope that your new tobacco plants manage to entice at least one to your garden.

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  2. Hi. I'm almost certain we just found one of these in our garden,it was in the middle of our path so I carefully picked it up and it just sat still on my hand so I got my camera and took some pics as I've not seen a moth that size in the wild before. Was a really lovely surprise to see it. We live in Salisbury,Wiltshire so I don't know if it's uncommon for it to be in this area at this time of year (June)
    Best wishes
    Sue

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  3. Hi Sue, I don't think they're common anywhere, Sue. I'd love to see a live one - especially in flight. Thanks for visiting. Best wishes,
    Phil

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  4. I have a live one at the moment found it on a fence today so moved it to stops kids causing harm to it I think this is a convulvulos hawk moth I have picture of it if anyone wants to see. Also to confirm that is the name of this moth, are these rare moth,

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  5. Hi Sammie, They are certainly rare in Britain - I've never been lucky enough to see a live one!

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