This year, rather than having to stare at little net bags dangling on bits of string for hours on end, I've decided to use traps so that I can get on with other matters while the pheromones are doing their thing. Having left the MYO and VES pheromone lures out in the garden here yesterday without any success, today I tried the same with TIP and FOR and a single Currant Clearwing came to the TIP lure. Of the species I've had in the garden, this is the one most likely to appear in that I've now had records of it on five occasions (the first was in 2009). Nice to see again, all the same! In the first picture you can just about make out the moth silhouetted against the base of the yellow funnel and shows just how small it is.
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| Pheromone trap, Westcott 17th June |
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| Currant Clearwing, Westcott 17th June |
Dave Wilton
Westcott, Bucks
Hi Dave, interesting to see your trap. I have an identical one, and I have always put the lure in the small compartment in the lid. You seem to have your lure placed in the bottom, which I guess is more likely to entice the clearwing into the container. I shall have to try that. I wonder though if the pheromone disperses as well if it is sitting in the bottom of the trap?
ReplyDeleteHi Steve, my most recent lure is in the compartment in the lid while a couple of older ones (which I'm pretty sure still work) are in the bottom. I've purchased new lures roughly every three years, probably unnecessarily and I've always kept the older ones.
ReplyDeleteI was concerned that moths might just dance around at the top and not end up inside the trap because some species seem to work out very quickly that there isn't a female present and just leave. Having a further supply of the pheromone at the bottom would, I thought, make sure that they are enticed inside. Probably overkill and I don't yet have much experience to go on with the trap, only having had this one success with it so far!
I think these traps may well depend on the species. They are not well designed for those species that spend little time at the lure. I have one, albeit not identical in coloration (it is green throughout) and used it on my apple trees over the weekend where there is a known population of red-belted clearwing. I watched it for 5 mins and 3 males came and went into the compartment with the lure in but never went below it and so never entered the 'trap' part, and after having it hanging for the whole afternoon not a single male ever ended up in the trap. If I hadn't watched for 5 mins I would have concluded 'no clearwings'. I also used a different type of trap (but based on the same principle, i.e. lobster pot) last year for six-belted. As you know lots of males come very quickly but I wanted to crack on with butterfly transect and so left a trap out. After several uses in known locations for the moth I had one in the trap on one occasion. Sitting and watching the lure in the other locations where I had false blanks confirmed they were indeed most often false blanks. So useful if no time to sit and watch but not a good way of concluding an absence. Also, I would argue that if you have to leave a pheremone out for longer than xx minutes in a location then you're probably drawing males from somewhere much further away as the scent plume drifts over time and thus you are not actually getting a site record you're just getting an addition for a list = often a false record. A tricky one and I;m sure I read an article somewhere about how long you should leave one out but I can't remember and I guess you have to factor in wind etc.,
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