Category: Lepidoptera

UPDATE: My report of Orange Tip on 2024-03-17 may well have been the first reported nationally this year, according to our County Butterfly Recorder.

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I saw my first Orange Tip (Anthocharis cardamines) of 2024 on 17th March in Cottenham patrolling a roadside verge (Broad Lane).

This was the first report for Cambridgeshire and Essex butterflies this year, apparently. I have to admit I’ve not kept a personal record of first sightings of this species, but the Cambs & Essex page does, so I can give you a list of previous years.

4 Apr 23, 24 Mar 22, 30 Mar 21, 26 Mar 20, 28 Mar 19, 17 Apr 18, 28 Mar 17, 8 Apr 16, 8 Apr 15, 24 Mar 14, 25 Apr 13, 26 Mar 12, 24 Mar 11, 11 Apr 10, 5 Apr 09, 21 Apr 08, 12 Apr 07.

So, it looks like my sighting is the earliest Orange Tip of the year in our Butterfly Conservation sector since they started recording public records on those pages. Previous earliest was three years where it appeared on 24 March, i.e. a week later. I posted on Twitter about the sighting and the tweet garnered a lot of interest.

Someone asked if there were wild brassicas, such as Cuckoo Flower (Cardamine pratensis) or Garlic Mustard (Alliaria petiolata) plants in bloom in our area. As far as I know, there aren’t. Indeed, the wildest it gets on that roadside verge is probably with the presence of Common Dandelion (Taraxacum officinale) and Common Daisy (Bellis perennis) unless someone has shaved it to the ground to make it all neat and tidy.

The lack of blooming wildflower brassicas (formerly known as crucifers) species, Cuckoo Flower or Garlic Mustard, could be a problem for early mating Orange Tips as the females are very choosy about the host plants on which they lay their eggs. They need large flowerheads from those wild brassicas and then generally plants that are growing in full sunlight. They don’t even like to fly through shade to find the plants, it seems.

Then there is the issue of egg colour and pheromones. When first laid, Orange Tip eggs are white but change to orange and then brown within days perhaps making their presence obvious to other females arriving at the flower. The female also covers her eggs with a pheromone that dissuades other females from laying eggs in the same bloom. This will benefit the larvae of both females as the original ones will not have competitors for food (the host plant’s seed pods), but also, the more recent eggs, and so younger larvae, will not be cannibalised by the older ones.

The weather patterns have been weird at this time of year for several years now. Think back to the warm days of March during lockdown. I’ve not seen any more Orange Tips yet, so this may have simply been a precocious male who may miss his chance of spreading his seed if no females appear soon. The main emergence may happen at the end of the month and into April, as is more usual.

 

First Oak Beauty of the year seen in the garden last night (6th March 2024). It’s a quite stunning creature, isn’t it? Sharp-eyed readers will note this is a geometer moth. So-called because their larvae (caterpillars), known as inchworms in the US, move in such a way as to give the appearance that they are measuring the earth, geo-meter, inch by inch.

You might also be thinking it looks like a Peppered Moth but with more colourful and more pronounced markings. Well, the Peppered Moth is a kissing cousin of this species, seen a little later in the year than peri-spring. The Oak Beauty is Biston strataria, the Peppered Moth is in the same genus, and is B. betularia. While the shape of the moth is very like the Peppered, the markings resemble those of some of the so-called carpet moths. By the way, they don’t eat carpets, but look decorative, like the luxury item that was a carpet back when the early lepidopterists were giving all these species their names.

An analysis of the genomes of more than 200 butterfly and moth, Lepidoptera, species reveals that genetic framework of what is ostensibly a very diverse group of insects, has remained remarkably stable since they diverged from their last common ancestor over 250 million years ago.

In a study published in the journal Nature Ecology and Evolution, shed new light on the evolutionary history and genetic structure of the Lepidoptera, which could help in conservation efforts for what is an incredibly important group of pollinators, food source for birds, bats, and other creatures, and a vital part of a healthy ecosystem and environment. I’ve discussed the importance of moths and mothing on Sciencebase before.

Despite the wide range of physical appearance and behaviour of the Lepidoptera, of which there are some 160000 extant species around the world, the team has demonstrated that 32 ancient chromosome building blocks, termed “Merian elements,” have changed little in 250 million years and remain consistent across most species. Even the arrangement of genes within these chromosomes has shown consistency over time.

However, some species, notably the Blue butterflies (Lysandra) and the White butterflies (Pieris), exhibited significant chromosome rearrangements, deviating from the typical genome structure. These exceptions offer insights into the mechanisms driving genetic diversity within Lepidoptera.

The study’s implications extend beyond entomology. By understanding the genetic foundations of butterflies and moths, researchers can inform conservation strategies. This knowledge could assist targeted conservation efforts, ecosystem health monitoring, and adaptation to environmental changes, particularly those related to climate change.

Additionally, this research aligns with broader initiatives such as the Darwin Tree of Life Project and the Earth BioGenome Project, aiming to sequence and understand the genetic makeup of all life on Earth. By unravelling the mysteries of Lepidoptera genetics, scientists contribute to a deeper understanding of biodiversity and evolutionary processes.

Understanding butterfly and moth genetics not only provides insights into their past but also lays the groundwork for more effective conservation strategies to protect these important pollinators and herbivores in our ecosystems.

Wright et al. (2024) Nature Ecol Evol – Comparative genomics reveals the dynamics of chromosome evolution in Lepidoptera

In the world of entomology, the naming conventions of moth species often reflect a fascinating interplay between scientific and vernacular language. While some moth species boast evocative common names like Angle Shades or Setaceous Hebrew Character, others, particularly those belonging to the category of micro moths, are identified solely by their scientific nomenclature, lacking universally recognized common names. This situation draws a curious parallel to the realm of dinosaurs, where species like Tyrannosaurus rex are known exclusively by their scientific designations.

However, amidst this taxonomy, there exists a notable exception: Diurnea fagella, a moth species that straddles both worlds of nomenclature. Officially classified by its scientific name, Diurnea fagella, this moth also bears vernacular names, albeit inconsistently. It is sometimes referred to as the March Dagger moth or the March Tubic, though within international and Lepidoptera communities, it is unequivocally recognized as Diurnea fagella.

This dual nomenclatural identity of D. fagella underscores the nuanced complexities of species classification and naming conventions within the field of entomology. While some species remain firmly entrenched in scientific terminology, others manage to acquire colloquial names, reflecting perhaps their significance or visibility.

Beyond the realm of moth identification, this phenomenon prompts broader reflections on the relationship between scientific precision and common language. It highlights the ways in which organisms are categorized, named, and understood by both experts and the general public. Moreover, it invites contemplation on the cultural and linguistic dynamics that shape our interactions with the natural world, illuminating the intricate tapestry of human-animal relationships.

You will know by now just how fascinated I have been these last 5+ years by the the section of the Lepidoptera we know here as moths…and also the moths we call butterflies. One of the most wonderful of creatures in this group is the Hummingbird Hawk-moth (not to be confused with the rather different US species known as hummingbird moths).

This moth, Macroglossum stellatarum, is present across Europe and Asia. It’s a day-flying species that nectars on lots of different types of flower. It does look like a tiny hummingbird, but of course those birds are only found in the Americas so don’t overlap with airspace here.

Anyway, a recent paper in PNAS discusses how the moths coordinate their proboscis, to feed and extract nectar from flowers. The research suggests that contrary to early theories, the moths use vision to coordinate proboscis movement, even though such complex eye–appendage coordination is unexpected in invertebrates.

Visually guided appendage reaching, such as hand to eye coordination in apes is an everyday part of our lives. It involves the perception of the relative positions of the object and the appendage in three-dimensional space as the appendage moves toward the object. That takes a lot of brain power and great eyesight.

Now, Anna Stöckl and colleagues tracked the movement of the proboscis of Hummingbird Hawk-moths as the moths explored artificial flower patterns. They found that the insects probed the visual patterns with their proboscis to a greater extent than a homogeneous flower background, suggesting visual guidance. The authors also compared the probing behaviour of the moths’ proboscis under occluded and free vision conditions. Vision occlusion impaired the moths’ ability to probe in alignment with artificial flower patterns, suggesting that visual feedback of the probing proboscis is required for targeted probing.

Visual guidance fine-tunes probing movements of an insect appendage, Proc Natl Acad Sci (USA), 2024, DOI: 10.1073/pnas.2306937121

Looking forward to seeing this Sundance documentary:

Nocturnes (India, USA) directed and produced by Anirban Dutta and co-directed by Anupama Srinivasan. From the Sundance Festival website:

“In the dense forests of the Eastern Himalayas, moths are whispering something to us. In the dark of night, two curious observers shine a light on this secret universe.”

This unassuming little moth has a suitably unassuming little name. It is known as the Winter Moth. It is one of the geometers, or what is referred to as inchworms in North America, because the larvae seem to measure out the earth as they move inch by inch.

The Winter Moth is not to be confused with the November nor the December Moth. It flies at the opposite end of the season to most other moths – October to December and sometimes into January and even February. It is unlikely to ever cross paths with the Spring Usher, the May or July Highflyers although it may well overlap with the Autumnal Moth and perhaps even the Autumnal Rustic, and definitely the aforementioned November and December.

While its common name is rather unassuming and perhaps obvious given the season in which it the males are on the wing (the females are flightless), this belies a resilience and a resistance to the cold that many other creatures do not display. Indeed, while some warm-blooded mammals from hedgehogs to bears will seek out shelter and hide themselves away from the ice and snow during hibernation, this little creature is searching for a mate. Incidentally, the females simply crawl up tree trunks and exude sex pheromones to draw the attention of amorous males.

The females then lay a couple of hundred eggs in crevices in the bark of trees. The larvae don’t emerge until the spring when the daytime temperature reaches about 10 degrees Celsius. Historically, this would have been perfect timing for the larvae to feed on the newly opening leaf buds of their host trees. But, with climate change, that temperature is consistently reached several days before those tasty leaf buds have begun to appear. As such, many larvae that emerge when the temperature rises and the leaf buds have not yet opened simply starve. Evolution, however, has a way. There is evidence that some larvae that incidentally hatch later, when it’s warmer still, can feast on leaf buds. As such, they survive to mate as adults in the winter and so pass on their genes. Among those genes will, of course, be the ones that trigger them to emerge when the temperature is a little higher and so coincide with the opening leaf buds.

The moth’s scientific name is Operophtera brumata, the brumata meaning “short” and alluding to the length of the days at this time of year. I am not 100% certain of the etymology of the first part of the name, the genus Operophtera. Opero could mean I work and the second half could be “to destroy” from the Greek, or it could be a tweak on “wing”, which can be ptera or phtera, I believe.  So, it could mean “I work to destroy” or “I work my wings”. Given that the larvae can ravage a small tree’s foliage leading to a halving of the tree’s growth that year, perhaps “I work to destroy” is apt.

I’ve recorded Winter moth since I began nothing, but not every year and only one specimen per season – 2018, then 2021, 2022, and now 2023.

For US readers, the closest relative is the Bruce Spanworm, Operophtera bruceata.

This is a November Moth…or a Pale November Moth…or maybe an Autumnal Moth…it’s definitely one of the Epirrita species of moth, but I, and almost nobody else could tell you for sure which from this photo.

But, it’s is one of those moths that could be any of several different species. You cannot know for sure unless you’ve raised it from larvae and know for sure what species you had, or you’ve done DNA testing but that assumes someone has the genomics for the various species, or you’ve done what lepidopterists call “gen det”.

Gen det, genital determination is where you dissect the male moth’s genitalia. Moth genitalia are markedly different even between otherwise very similar species and so you can identify which species you have from the bits you chopped up.

I am not going there.

So, my records simply say Epirrita agg, meaning an aggregate of all the possible species in the UK and no positive ID for any of them in particular.

There is, however, another British Epirrita species, the Small Autumnal Moth, which as the name would suggest, accurately for once in taxonomy, is actually smaller than the others and its wings markings are stronger. If you have one of those, you can assume you’d be able to distinguish it from the other three Epirrita species.

I saw my first Merveille du Jour (Griposia aprilina) in the autumn of 2019, a year after I started mothing. A couple have turned up to my 20W actinic Skinner trap in October 2023. I photographed the first without props, but this morning, despite my head cold, I cycled to the local woodland to forage for a few lichen-encrusted oak twigs and leaves for a more authentic photoshoot. The moth’s larvae feed on oak (Quercus) flowers and later leaves.

First appearances for Merv in our garden

2023 – 8th October
2022 – 22nd October
2021 – No show
2020 – 14th October
2019 – 5th October
2018 – No show