Monday, 25 September 2017

A mega moth trap

I have often fantasised about taking the moth trap on holidays abroad - an impossible dream because it is much to big and cumbersome to ferry around, even if we were to go by car. Likewise, I have sometimes gazed wistfully at advertisements in entomological or natural history magazines for cottages and villas to let on the Continent which come complete with a moth trap. Penny would draw the line at that.

However, on our week in Portugal from which we returned yesterday, I did indeed have a moth trap - and a very big one. Our hotel's swimming pool was set in lovely, rather wild gardens and its underwater lights were left on all night. You can see some of the results here. Come the morning, several dozen moths were suspended on the pool's surface, clamped like prisoners by the surface tension and moving slowly but surely towards the doom of the filter outlets.
Update: the expert and kindly guru of Upper Thames Moths, Dave Wilton, identifies this as a Dusky Carpet, a moth only once recorded in the UK, a specimen caught at Tenby in South Wales which is now in the Museum of Natural History in Kensington

I learned after a couple of early morning swims that it was handy to get to the pool before the gardener/handyman who dutifully netted debris from the pool first thing. I enjoyed chatting to him in a strange mixture of English and something vaguely like Portuguese although probably tending more towards Spanish. But although we got as far as 'mariposa' and 'borboletta' - words in both languages for 'butterfly' - I didn't try to complicate his life by appealing for a netting delay while I waded about with the iPad Mini, taking pictures.

A Yellow-tail - a species notoriously shy about showing its eponymous feature. This one had little choice.

The answer was to have my swim a little earlier. I managed to do this and even to build in time to rescue most of the apparent victims. The moths looked dead, apart from one or two which were struggling feebly, but once you scooped them out and decanted them on to the stone, decking or even nearby tree-trunks, they recovered speedily. Here are some examples:

I think that the bottom moth is a Portuguese example of the Yellow Belle, a moth which is only locally found in the UK - one of the locales being a regular stamping ground for me in my journalism days: Greenham Common near Newbury, scene of the famous women's protests against cruise missiles.

I have yet to discover the ID of most of the moths shown in this post, but this one is a Portuguese example of our familiar Scalloped Oak. I think, incidentally, that the moth in my top picture may be a Portuguese Straw Belle. Update: no, I have changed my mind and think that it is the yellowy form of the Vestal.

My most curious observations, however, were of a half-dozen or so moths which were perched at least an inch underwater, clinging to the side of the pool, thoroughly alive and apparently contented with their surroundings. When I eased them off and put them down in the sunshine, they too recovered. There is plenty on the web about moths and other insects' ability to spend time underwater, including a piece on a Hawaiian moth which seems happy in both elements. There is also the example of dragonflies, whose first three stages of life are spent in water. But I hope to read more, not only about the breathing issue but also about the waterproof-ness or otherwise of moths' wings - note the bubbles of air clinging to the ones below. In butterflies, which are generally larger and more delicately made, these would seem the main vulnerability of a dip, but there seems reason to believe that the complex structure of scales and membranes is water-resistant, provided that the insect does not panic and thrash around.  


Anonymous said...

Oh yes, a particularly non-mediocre post today

Great entomological enthusiasts think alike, and I fantasize about vacations and use my pool as a pitfall trap as well. Spiderwebs sometimes make good traps too, because sometimes captured insects are ignored by the spider and appear to be in perfect health. Although I do not believe in deliberately making traps which can harm insects, I will gladly take advantage of preexisting ones. In fact, both of my current pet beetles (and many more past captives) were caught in a pool and a web, respectively.

And I too have seen many pillbugs, spiders, weevils, and even a winged aphid (!) walking around underwater, apparently unaware of their strange situation. I have also seen overconfident dragonflies fall into the pool while performing maneuvers and somehow fly off unharmed. I suspect that the first waterbeetles, fishing spiders, and pond-measurers developed from insects which could take advantage of these happenings.


AlexW (locked out again of account from fear of spyware)

Anonymous said...

Edit: speaking of fear, I just noticed that your blog list needs some revisions. "Dean's blog" seems to have been infected and killed by parasitoid wasps in the family Cyberbraconidae. It is filled with what appears to be Indonesian spam.


Martin Wainwright said...

Hi Alex - interesting points about insects and water -and thanks for the links check. I'll find time to sort that out one of these days. All best M