Posted: Saturday 16th June 2018 by Twheatear

Mocha moth

An unexpected moth nearly gets away...

When running a moth trap, it’s worth looking around the trap as well as inside it. Some moths may have been attracted by the light but not managed to find their way into the container beneath it. So when I sleepily went out to close our trap at 5am last Friday, I noticed a small white moth clinging to a grass stem. It went into a pot, I went back to bed for a bit more sleep.

After breakfast we discovered something rather special. My moth turns out to be a Mocha – a nationally scarce species that was recorded in fewer than 100 10Km squares between 1980 and 2003. I’d find it hard to believe that we had such a rare creature in the garden, but the field guide is unequivocal: “similar species: none”.

Mostly it’s found in the south and east of Britain, with Wales at the northwest edge of its distribution. Here, too, it’s a moth of south and east: ours in Abergavenny seems to be about 10 miles further northwest than any previous Gwent records. This limit doesn’t seem to be related to food plant: the caterpillars eat the leaves of field maple, which we have in the garden. It seems more likely to be limited by temperature so its arrival here may be a sign of climate change.

The slightly damaged and faded (newly emerged mochas are even more spectacular) condition of ours suggests that it has been flying around for a while. With luck it has already managed to find a mate so we’ll be keeping an eye out for more in future.

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