A couple of days ago I purchased a max/min thermometer so that I can record the minimum overnight temperature in order to assess the affect that this has on the number of moths trapped. I thought that the minimum of 6.8 C on 7th was low, but last night (8th) the recorded temperature fell to 2.2 C, which is obscenely low for this date in June, and perhaps accounting for the total of just 7 moths across two traps! Unfortunately, cold air always seems to get funnelled into my garden, as it lies at the bottom of three converging slopes.
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Hi Keith,
ReplyDeleteYes, it must have been a record low temperature here too for June on the night of the 8th because I managed only 10 moths of 8 species between two traps. Even though it was far from being warm in last night's rain, there was at least some cloud cover which meant that the temperature stayed just into double figures and there was a marked difference in the traps with 110 moths of 50 species. However, even that total is poor for this time of year.
I would be wary of the accuracy of your thermometer! With a reading of 2.2 C I assume it is an electronic one? I bought one such a couple of years ago but found it to be a long way out when checked against other thermometers, so I got rid of it. I later looked to buy another (from a garden centre), but noticed that although there were several on display they all read differently, so I gave up!
ReplyDeleteI have a very old mercury max/min that I trust having roughly checked its calibration, but I don't think you can buy them any more.