Category: Biology

The Box-tree Moth (Cydalima perspectalis, Walker, 1859) is an invasive species that has reached the British Isles. It originated in Asia and its larvae feed on, as the name would suggest, various species of Buxus, box tree (known as boxwood in the US). It turned up in my scientific trap night of 11th July 2019. I almost missed logging it as it flew up to a window as I was opening the trap. I’ve sent a record to the Cambridgeshire County Record.*

It’s a pretty pearlescent moth and was first seen in Europe in 2006, in Germany, specifically. It is most likely to have hitched a ride on imported Boxus plants as eggs or larvae. It was first recorded in the British Isles in Kent in 2007, spread to Surrey, into London and the home counties and beyond. It is not known which counties it is now resident in, but there have been sighting, often to moth traps, across most of Southern England and further North. It has been recorded in Fife in Scotland. Spotted in Toronto, Canada in 2019.

The larvae will devour Buxus leaves and so disfigure ornamental and topiaried Buxus. Of course, it is the importing of particular species of these plants that has allowed this moth to spread, reinforcing the mantra that planting native species should be the ethical horticulturalists way forward.

* Bill Mansfield the County Moth Recorder got back to me this morning with a response to the Box-tree Moth sighting:

Box tree is pretty well established in Cambridge city from Trumpington to North Cambs so no surprise you've got it too. I dread it arriving in Ely, if it's not already here. I've 20-metre of box hedge I've nurtured for eight years against everyone's best advice...

Amateur Lepidoptera expert friend Leonard has not “ticked” one of the species that were new to me in last night’s scientific trap experiment. The species in question looks quite remarkable: Marbled Clover, Marbled Clover (Heliothis viriplaca). So, that’s bonus points to me today, surely?

In fact, a day later, it seems that quite a few of the experienced moth-ers on the Facebook group there have not seen this species. It usually inhabits The Brecks, but there is evidence that there are migrants. We’re not that far from The Brecks here, but this could well be a traveller that just turned up almost randomly here.

Overall the haul for the night of 10th July 2019 and into the morning was more than 210 specimens of more than 56 moth species. There was a lot also among the folds of the white sheet I have hanging by the trap.

It would be interesting to know whether the sheet really makes a difference, as there are several species that don’t seem to enter the trap often that I have seen in the dark close to the trap (the large, lemon sherbert coloured Swallow-tailed moth, for instance), but are attracted by the ultraviolet let, and simply hang around the folds of the sheet. But they might just as easily roost on the brickwork and glass of the conservatory, in fact some do. Old Lady has appeared in the trap twice now (different specimens) and they’re not really even meant to be attracted to light.

I also wonder if all my wildflower planting and cultivating night-scented plants (Nicotiana, Stock) in the garden is making a difference, attracting moths by scent that are then drawn to the UV. I only started this experiment at the end of July 2018, so it is impossible to know, and the weather was very different in the summer of 2018, so there’d be no comparison even if I had started earlier and kept detailed records then.

Either way, I’ve just passed 250 species identified and photographed. This, I’d say is the half-way mark, given that two other moth-ers in the village here are both at the 500 mark after several years of scientific trapping.

If you want to follow the detailed logging of the experiment, my spreadsheet is available here.

All of the photos on this blog post are of species new to me on the day or writing. 11th July 2019.

In case you hadn’t noticed, Sciencebase is now moth central, at least for the time being. I’ve been using a scientific trap with a 40W actinic UV light for almost a year now. Have identified (often with help) and photographed almost 250 different species of moth. That’s a mere 10 per cent of the number of species seen in the British Isles. Some rarities have been seen beyond the trappings of our back garden too, including the Brassy Long-horn, logged with the County Recorder and back in the trap, Light Feathered Rustic.

Anyway, this morning’s haul was quite vast. Biggest count ever – 200+ moths of 50+ species (not counting a few stray micro moths). I managed to ID all but one of them. The spare one isn’t in my Collins guide to Lepidoptera. It’s a micro moth known as a Meal Moth, Meal Moth (Pyralis farinalis).

The Meal Moth is not normally interested in lights and usually spends its time in buildings (what it did before buildings I don’t know…caves…woodland hollows, presumably). Its larvae eat stored grain, so the kinds of buildings it prefers are grain stores and barns. Now, we’re not too far from farmland and some of the local crops are wheat and barley, but there are no grain stores close to us. It might be that this species, rather than being a dingy building dweller is something of a scarce migrant. Neil Croton on one of the mothing Facebook groups ID’ed it for me and told me he’d had the same species last night too:

It's a lovely-looking moth, deserves to be a rare migrant rather than an overlooked moth of old farm buildings

I sent a record to Bill Mansfield the County Moth Recorder for Cambridgeshire (VC29). He told me that the Meal Moth turns up consistently and he had noted a recent mention on social media for Cambridgeshire.

UPDATE: June 2021 – I have recently negotiated with the UK Environment Agency to reschedule the mowing of the Lode banks on which this moth has been thriving these last two or three years – Saving Lode Life.

A gentle tale of heavy metal insects…a summer walk along the flood-bank of Cottenham Lode, usually with a camera, often turns up an interesting bird or two, Reed Warblers, Skylarks, Reed and Corn Buntings, and their cousins the Yellowhammers. There are often Linnets and various raptors and herons.

Earlier this week, I was chasing butterflies – Meadow Brown, Skipper, Painted Lady, Red Admiral, etc. A rather mundane and almost throwaway snapshot of a Green-veined White perched on the Field Scabious on the bank of the dog-leg in the lode where it deviates towards Rampton Bridge turned up something interesting. I thought I’d spotted a hoverfly, but when I looked at the photo closeup, it turned out to be a moth with very long antennae.

I tweeted the photo @MothIDUK who could only pin it down to one of various Nemophora species. It wasn’t his fault, the overblown reflections of the moth’s forewings hid any detail. However, Ian Ellis, a fellow moth-er in Cottenham, saw my tweet and went to the Lode himself to check out this day-flying moth. He saw eight longhorns and reckons the one in my photo is Nemophora metallica. A great moth name for heavy metal fans, one has to admit.

I took another trip to the dog-leg in the Lode and photographed the species again, this time deliberately and with a tripod so I could get some fairly sharp photos where I was homing in on the moth rather than random butterflies. Amazing creature, the male’s antennae are about three times the length of its body, although its body is just 8 or 9 millimetres long, but…still!

In my photos, the moth is feeding on its target plant, the field scabious, Knautia arvensis. They’re known in East Anglia, but relatively rare and this could be a useful record for Cambridgeshire, VC29.

Any moth-er will tell you, a lot of moths are shit…that’s not to say they don’t like them, rather lots of moths have evolved to resemble bird droppings. Among those that have camouflaged themselves as guano are the wondrous Chinese Character, the Lime-speck Pug, the Least Carpet and the Garden Carpet, and several others. They are unaware of their superficial resemblance to a dollop of tacky avian ordure. Anyway, it’s what’s on the inside that matters and moths have feelings too…sort of.

Other moths have a grander perspective on camouflage, Buff Arches, as previously mentioned looks like a chunk of knapped flint and so can hide among the stones on the woodland floor with predators unaware of its presence.

But, today I want to talk about a sticky moth. I don’t mean the species has adhesive qualities, although if you let it walk on to your finger you can feel it clinging on to your skin. No, the moth we know as the Buff-tip looks like a piece of broken twig. A twig from a birch tree to be precise. Unfortunately, the best twig I found was from our wisteria, so he had to make do. In my first photo, it is difficult to see where moth and twig begin and end. Is that twiglet the alpha to the moth’s omega or its yang to its yin? You decide.

In this photo, the moth was still clinging to its twig, almost for dear life, and in my photo it’s more obvious which is which, but…are you sure, you’re seeing it the right way?

As the summer moves on, so the diversity and numbers of moths (Lepidoptera) active each night grows. We’re coming to the end of the first week of July and already one night’s haul has passed 200 specimens of 40 different species, logged, identified, and the interesting and ones new to the garden photographed.

160+ moths of more than 30 species were drawn to the actinic light of the scientific moth trap on the night of 5th July. I had heard and possibly seen an Old Lady (Mormo maura) in the garden a few nights ago, but this morning she was nestled in one of the egg trays in the trap awaiting her photocall. This species is large (30mm along the edge of the forewing). Far bigger than the many micros that I didn’t log in detail. You can see the morning logs for the leps here.

The Old Lady, also known as a Black Underwing, and in an earlier time, the Grave Brocade, was accompanied by two Privet Hawk-moths (the UK’s largest species of moth) and a single Elephant Hawk-moth both of which I’ve photographed and written about here previously. The Old Lady is not commonly drawn to light according to the UK Moths site, although my Collins lep guide says they will often come indoors attracted by the light. Regardless, this one definitely was drawn to the light and settled in for the night. It had a chunk missing from its left forewing, so I did a little ‘shopping to tidy her up.

Why is this noctuid, or owlet, moth, called Old Lady, you are probably asking? Well, the sombre answer is that the dark and funereal colours of this moth reminded those who named it of the penchant of elderly widows of Europe for wearing black. This was long before the Victorian era though.

The delicate patterning of the moth’s wings, according to Peter Marren in his book of moth names, Emperors, Admirals, and Chimney Sweepers, resembles that kind of black lace. Intriguingly, adds Marren, the scientific name – Mormo maura – The first part of the name is the name of a hideous she-monster used by Greek parents, apparently, to encourage errant children to behave. “Mormo will come and bite you, if you don’t behave! The second part of the name alludes to the Moors. In Holland, the Old Lady, Marren tells us, becomes a black orphan – Zwart weeskind.