Category: Stu's Top Moths

Stu's top moths: week 12 - Common or garden moths

1/9/2014

Each week we hear from Master's student Stuart Brooke r who traps moths in the woodlands around Durham University. Stuart identifies, records and photographs the moths he traps, and provides CEG with a weekly update of his trapping efforts.

Here is Stuart's week 12 report:

Following a rather promising first half of the ‘main’ mothing season, the second half is turning out to be a bit of a damp (and breezy) squib. There was no improvement in the weather for Week 12, and no improvement in the diversity and abundance of the catch. So, now seems like the perfect chance to show off some of the more commonly recorded species.

The Large Yellow Underwing (Noctua pronuba) is probably the most frequently recorded moth of my trapping sessions in the university woodlands so far. It is also the most frequently recorded species on the entire database for County Durham, and it is the second most frequently recorded species - after the Heart and Dart (Agrotis exclamationis) - in five years of trapping in my garden in Essex. This is undoubtedly among the most widespread and common of our moths, and familiarity with it certainly breeds contempt. But hold on a second ... before we tick off our 100th N. pronuba of the session and launch it unceremoniously back into the shroud of night, uttering under our breath “another Large Yellow Underwing; they’re so common", maybe we should pause, allow the moth to rest on our finger (if it will, they’re flighty at the best of times), or sit it in its pot. Let's ponder over it for a moment.

This a very variable species, with a number of colour morphs within a population; the individual we hold now may look different from the last, or the next. This is possibly an adaptation to predation pressure, whereby species that occur in high densities exhibit high colour polymorphism as an anti-searching image response. I’ll elaborate: predators may develop a search-image of commonly occurring prey. However, if the prey item exhibits a spread of different colour and pattern morphs throughout its population, the local predators will either need to build a catalogue of several explicit search-images, or make do with a general, and rather vague, search-image of its prey – either way, being variable has its advantages. If this isn’t enough, behind its cryptic, and frankly, fairly dull facade, is more defensive weaponry – a flash of its bright, contrasting ‘yellow’ hindwings is designed to startle hunters on the prowl. What’s more, the moth we hold can detect foraging bats (Windmill et al., 2006) often before they can detect it, and is capable of navigating by the moon, the stars and the earth’s magnetic field (Baker & Mather, 1982).

So, now we’re ready to release our moth back into the night, perhaps instead we might utter “another Large Yellow Underwing; they're so common ... and they're a marvel of evolution”

The Mother of Pearl (Pleuroptya ruralis) has been one of the most commonly recorded of the micro-moths in the woodlands so far; and because of its size, it is one of the more obvious. The species is a good example of why the term ‘micro-moth’ is not always appropriate; with a wingspan of up to 40 mm, it is as large as many of the macro-moths, and superficially resembles those of the family Geometridae. Its larvae roll up the leaves of common nettle (Urtica dioica) and feed upon them from within; all the while, attached to a thread of silk. When threatened, the caterpillar dashes from its tubular domicile and dangles from its silken lifeline.

Despite its common name, the Common Carpet (Epirrhoe alternata) has not been hugely numerous within the woodland, but instead has occurred in a steady stream of modest numbers; with the first generation visiting the trap throughout May, a break during June, and the second generation showing from the beginning of July up to the present.

The Canary-shouldered Thorn (Ennomos alniaria) is so named for its bright, canary-yellow thorax. The moth's speckled underwings resemble birch leaves as they turn yellow in the shortening days of Autumn; thus, providing camouflage for egg-laying females - whose offspring will feed on the tree next Summer. This is the fifth of the ‘thorns’ recorded in the woodland so far - the others being Lunar Thorn (see Week 5), Early Thorn, Purple Thorn (both Week 9) and Dusky Thorn (Week 10). This species is widely-distributed and frequent throughout Britain.

Stay tuned weekly for more 'Stu's Top Moths' or follow us on twitter for updates and photos of moths and other wildlife around Durham University!

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Stu's Top Moths: Week 11 - Little brown jobs?

13/8/2014

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Every week we hear from Master's student Stuart Brooke r who traps moths weekly in the woodlands around Durham University. Stuart identifies, records and photographs the moths he traps and provides CEG with a weekly update of his trapping efforts.

Here is Stuart's week 11 report:

The unsettled weather of week 10 continued into this week, and, if anything, night-time temperatures fell away further; leaving the mornings feeling, dare I say it, a little Autumnal. These conditions undoubtedly adversely influence moth survival and activity, and this was reflected in this week’s catch, which was the lowest in terms of both species and individuals since the first week of June. Nevertheless, there were still a number of interesting species well worth showcasing.

The ‘Top Moths’ this week all just happen to be micro-moths. The division between micro- and macro-moths is a rather arbitrary one, reflecting traditional practice rather than taxonomic-correctness; although – with the inevitable exceptions – many micro-moth families are considered to be more primitive than those of the macro-moths. Micro-moths could be considered as the ultimate LBJ’s, and are often overlooked or ignored. However, in both form and ecology, the 1600 or so UK species are fascinating and diverse. What’s more, when viewed up close, many are revealed to be every bit as attractive and intricate in pattern as their bigger relatives.

The Bee Moth (Aphomia sociella) may look the picture of innocence, but this species is a parasite of wild social bees – especially bumblebees (Bombus spp.) – and wasps. The species is also notable for having an unusual breeding behaviour, whereby males initiate courtship by emitting both acoustic and pheremonal signals to attract mates. Following mating, the female enters a bee nest to lay up to 100 eggs. Once hatched, the caterpillars may end up destroying the nest by consuming the brood comb and the bee larvae within (Kalinová et al. 2009; Kindl et al. 2012).

Apotomis betuletana is one of a number of small moths that have evolved a cryptic colouration that lends them the appearance of a bird-dropping. This less than glamorous masquerade is particularly common within the family Tortricidae (but not confined to it), and there even exists a guide book dedicated to them. For those familiar with the scientific names of trees, it would be no surprise that the larvae of this particular species feed on the leaves of birches (Betula spp.).

Shining golden-brassy, the typical colour form of Argyresthia goedartella is unmistakeable. This exquisite little moth is common and widespread throughout Britain – with the exception of the far northern Isles. Like Apotomis betuletana, its larvae feast on birches, but instead they burrow into the buds or catkins and feed from within.

Ypsolopha parenthesella exhibits a number of variations in both pattern and colour and some of the plainer forms could possibly be confused with other species, but the typical form with the large white marking – as shown in the photograph – is distinctive. The species is adapted to feed on a variety of tree species, a trait that no doubt contributes to its common and widespread status.

So, it turns out that micro-moths can be serenading bee-nest wreckers, bird-poo imitators, or decked-out head-to-toe in Christmas wrap ... boring Little Brown Jobs they most certainly ain’t!

Stay tuned weekly for more 'Stu's Top Moths' or follow us on twitter for updates and photos of moths and other wildlife around Durham University!

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Stu's Top Moths: Week 10 - Have you heard the one about the old Lady and the Copper?

8/8/2014

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Masters student Stuart Brooke r has been trapping moths for 10 weeks in the woodlands around Durham University. Stuart identifies, records and photographs the moths he traps and provides us with a weekly update of his trapping efforts.

Here is Stuart's week 10 report:
"The weather became unsettled this week, and night-time temperatures fell off slightly from those of prior weeks. Nevertheless, on the evening of 30th July, forecasts informed that there would be no overnight rainfall or through the following morning – so, confidently, I left my trap quietly doing its business in its usual spot in the woodlands. However, when I looked out of the window in the early morning, I witnessed the aftermath of a great deluge! As I walked to the trap-site, the small woodland stream, usually little more than a gentle trickle, was now a raging torrent. My fears where confirmed when I reached the trap and saw that the mercury vapour bulb had shattered (but still burning bright). Inside the trap, a set of soggy cardboard egg cartons provided limited shelter for over 300 weather-beaten moths. Two-thirds of the catch was either a Bird-cherry Ermine (Yponomeuta evonymella) or a Large Yellow Underwing (Noctua pronuba) – two very common and widespread species that evidently occur in good numbers and find light irresistible.

In amongst the Ermines and Yellow Underwings was a single Old Lady (Mormo maura). This large moth is unmistakable, even when most of its markings have been worn, or washed, away! It is widespread in Britain but described as ‘local’ rather than common. However, although it may be drawn by light, it enters the trap infrequently, and as such, may be under-recorded by trappers. Svensson’s Copper Underwing is a moth of similar hue to the Old Lady. In contrast however, it looked very ‘fresh’ and its colouration was deep and rich. The species is very similar to the closely-related Copper Underwing (Amphipyra pyramidea), but a combination of subtle features suggested this individual was very likely to be A. berbera. Other infrequent visitors to the trap this week included a new addition to the list of ‘thorns’ (see weeks 5 and 9 for others) – the Dusky Thorn, a Small Phoenix and Oak Nycteoline – a diminutive macromoth that, when I placed it on an oak tree to photograph it, it wrapped its wings around the shoot to hide its outline and promptly ‘disappeared’."

Old Lady (Mormo maura)

Svensson's Copper Underwing (Amphipyra berbera)

Dusky Thorn (Ennomos fuscantaria)

Small Phoenix (Ecliptopera silaceata)

Oak Nycteoline (Nycteola revayana)

Stay tuned weekly for more 'Stu's Top Moths' or follow us on twitter for updates and photos of moths and other wildlife around Durham University!

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Stu's Top Moths: Week 9 - A rose between two thorns

29/7/2014

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Masters student Stuart Brooke r has been trapping moths for 9 weeks in the woodlands around Durham University. Stuart identifies, records and photographs the moths he traps and provides us with a weekly update of his trapping efforts.

Here is Stuart's week 9 report:
"Two species of ‘thorn’ were recorded in good numbers this week. Typical of the thorns, both species adopt resting postures unusual amongst moths. The Early Thorn with its wings pressed tightly together above the body, much like a butterfly, reveals the cryptic colouration of its underside, resembling a dead or decaying leaf when clinging to a twig. The Purple Thorn, like the Lunar Thorn featured in Week 5, rests with its wings held open, half-raised and ‘curled’, creating a bowl-like shape. It can be distinguished from the Lunar Thorn by the dark central spot on the upperside of the hindwing, which incidentally, has a less deeply-scalloped outline. The larvae of both species feed on a wide range of woody broadleaved plants, allowing them to colonise various habitat-types, including urban parks and gardens.

Debutants recorded this week included the Antler Moth – so called for the elongate white antler-like marking that runs down the centre of each forewing – and single specimens of the Purple Bar and the Barred Yellow - both of which looked rather ‘tired’ and had lost the deeper colouration they would have had when newly emerged... but attractive nonetheless. These species’ larvae feed on grasses, bedstraws (Galium sp.) and roses (Rosa sp.) respectively; highlighting the importance of early-successional and open areas within otherwise mature woodland, allowing understory and herbaceous-layer foodplants to persist."