I realise it is a bit the worse for wear which doesn't help.
A few general questions.
1) When people use different bulbs/traps in the same location how do the catches compare? Although earlier in the year I was not finding a great difference between the 125w MV and the 20w Eco bulb now I seem to be getting nearly double the catch with the MV bulb on roughly similar nights.
2) For people who trap on all or most nights how often do you only get one record for a species in the season? At present I am trapping 3 or 4 times a week and seem to be getting quite a few single records.
3) What relative numbers of macro and micro moth species are usual in moth traps? I have only recently started identifying and recording micros and I know I have missed some but my present numbers are 117 macros and 34 micros this year.
Andy Newbold Sibford Ferris Oxon.
It's a Purple Clay. I'll let Mister Wilton answer your other queries as he is the Stats man.
ReplyDeleteThank you. So that is 118 macros!
ReplyDelete1.) The 125wt bulb is generally accepted to be the best at attracting moths, with the twin-30wt actinic arrangement quite close behind it, while other bulb types do attract moths but maybe don't perform quite so well. Depending on your level of expertise, having fewer moths to sort through can sometime have its advantages. Another consideration is that some moths seem to be attracted more frequently to actinic light rather than MV (and vice versa). Just as important, though, is the type of trap which you have under the bulb. The circular Robinson-type design is generally the best at keeping in all moths whereas the Skinner-type is less efficient at holding them and an unmonitored Skinner trap may result in quite a few escapees. That said, a regularly-monitored Skinner trap can be really good, in particular for micro-moths because they often tend to sit around on the perspex for a while and can easily be potted-up from there. It is really down to finding a balance between the amount of time you have available, what you can afford and whether or not the very bright 125wt light will upset any neighbours. It is also worth remembering that the EU has banned the production (although not the sale) of MV bulbs so just how long we'll be able to obtain them is open to question although there doesn't appear to be any significant shortage in supply at the moment.
ReplyDelete2.) I trap most nights and there are most definitely quite a few moths which may only appear once in a season. If you don't run the trap you'll never know what you might have missed!! I've been trapping in my present village garden since 2005 and thanks to the variety of habitats available locally the garden moth list is now close to 900 species, with additions still appearing every year. Looking just at the macros (total currently 411), there are 38 species which have only ever appeared here the once. Some of them are are migrants, certainly in these parts (eg Gem, Convolvulus Hawk, Silver-striped Hawk, Gypsy Moth, Small Marbled, Dark Spectacle), some are unexpected moths likely to be dispersing from their normal habitats (eg Royal Mantle, Pretty Chalk Carpet, Small Black Arches, Square-spotted Clay, Antler Moth, Brown-veined Wainscot, Silky Wainscot, Silver Hook, Beautiful Snout) while others are simply now quite rare species locally (Yellow-legged Clearwing, Oak Eggar, Tissue, Scarce Prominent). One or two are species in very serious decline (Spinach last noted 2007, Garden Tiger last noted 2009), while others are those increasing their range which so far have only appeared here the once (Red-necked Footman, Small Ranunculus, Tree-lichen Beauty, Marbled Green).
3.) June, July and August are the main months for micro-moth species so now is the time to be giving them extra attention. A really warm night might see the split 50-50 between macro and micro species, very occasionally with micros exceeding macros although that doesn't happen too often. You have far to go yet if the weather plays ball! If you get really keen, and depending upon what vegetation you've got in you garden, in the autumn you can turn your attention to looking for leaf-mines which is an excellent way (sometimes the only way) of adding some of our smallest moth species to your garden list.
Thank you very much for your very comprehensive and detailed reply. I was wondering what had happened to Garden Tigers remembering the days when the caterpillars were a common sight.
ReplyDeleteSadly, the Magpie Moth has gone pretty much the same way as the Garden Tiger - I remember cramming my jam-jar with the caterpillars when I was 9 or so.
ReplyDeleteAndy. - PS - A very good summary, Dave.