This stunning visitor flew through an open window at work today and came to rest on a treatment room wall: my first Red Underwing moth.
Red Underwing in the heatwave
Spring Moths 2019
We have been moth trapping at least weekly as we are contributing to the Garden Moth Scheme this year. Regular trapping in our garden in Headington, Oxford has increased our awareness of the seasonal change in moth species and numbers. Here are a few highlights of our catches in the period mid-March to 1st June. Let’s begin with some beauties!
A major highlight was our first Buff-tip for the garden (though we have seen them elsewhere). Everybody’s favourite moth, due to their amazing similarity to a broken silver birch twig, they just look fab from every angle:
Emperors emerging
Great excitement yesterday as our first Emperor Moth emerged. They are stunning moths, quite large, with obvious “eye” patches on both fore and hindwings, above and below. This fabulous female was one of a batch we raised on Hawthorn last summer:
Emperor Moths, from egg to cocoon in 6 weeks
Detail of the eye pattern on the upper forewing: 
Even from below, the “eyes” on the wings are visible. These presumably act as a deterrent, confusing potential predators into thinking that they are looking into the face of a much larger animal:
We transferred our Empress to a hawthorn bush across the road, one of the Emperor Moth’s host plants. It was the same bush that we fed the caterpillars from last summer. We left her there and thought that was it.
This afternoon, my wife took our children and some friends across the road to see if the female Emperor had moved. She had not. But even better, she had attracted not one, but two, males: 
Male Emperor Moths are smaller and more reddish than the large silver females. One male had succeeded in attaching his abdomen to the female. This was a rather worn individual, with evidence of some wing damage in comparison with the completely pristine, freshly emerged female: 
The male Emperors had located our female purely by scent. Their antennae are finely tuned to the pheromones that the female emits from her abdomen. I wrote about the wonder and sensitivity of moth antennae in this recent post:
The wonder of antennae
In over two years of regular moth trapping in Headington we have never caught an Emperor Moth. This was no great surprise, they are not easily attracted to light. Instead, the males spend their time seeking out females, tracking them down efficiently by following their pheromone trail. In less than 24 hours, our female had attracted two males, demonstrating the species is present in our local area. The male’s antennae are clearly visible here: 
Below, underwing details. The clasping mechanism at the end of the abdomen is visible. Each species of moth has evolved only to interlock with females of the same species. 
Below upperwing detail of the, slightly tatty, male Emperor:
A fantastic afternoon, with excitement for adults and children alike, present in the company of the Emperors.
The wonder of antennae
I am participating in the Garden Moth Scheme this year, so put out the moth trap in our garden every Friday evening and record our catch. This Friday saw a large increase in the number of moths and our first Oak Beauty: 
The antennae on this moth are fabulous, especially the white dots running along the shaft of the upper surface of the antennae: 
This got me wondering. Why do some moths have complex antennae, but most do not? Most moths have simple antennae. I was immediately encouraged to look into this. Partly because I have enjoyed photographing the amazing variations of antennae in our moth trap, but also because I have discovered that time stops when you start looking closely at moths.
A number of different antennae shapes have been recorded in moths (image © here): 
The majority of moths have simple antennae, like the Buff-tip, Poplar Hawk Moth and Brimstone Moths, below: 
Others have fantastic pectinate or bi-pectinate antennae arrangements, resulting in some truly fabulous headgear. Below, Dark Arches, male Muslin Moth and Pale Prominent: 
Antennae have that evolved over time to perform a wide range of complex functions. These not only include detecting members of the opposite sex through picking up traces of their pheromones, but antennae also have a role to play in providing flight stability. However, in evolutionary terms, antennae began their life as something much more simple: once they were legs.
The trochanter on the image above of an insect leg (© here), is at the junction between the body and the leg. In antennae this area has specialised to contain two wonderfully named organs: the Johnston’s Organ and the Böhm’s Bristles:
Johnston’s Organ (in the pedicle or second section of the antennae) detects motion in flagellum (the third and final section of the antennae) and helps provide flight stability. It is tuned to detect angular changes during maneuvering in complex flight, as demonstrated in Hawkmoths here.
Böhm’s Bristles appear to help control position of the antennae during flight. They are found at the base of the antenna and are tiny, but are visible in these images, labelled “BB” (© here):
The discovery that antennae help provide flight stability in moths is relatively new. Moth antennae are best known as organs of smell. They are highly specialised olfactory organs and can be incredibly sensitive. Amazingly, Indian Lunar Moths have been shown to be able detect a single sex pheromone molecule at a distance of 11km (6.5 miles), see here.
But if that is the case, then why do the majority of moths have simple filamentous antennae and only a minority a more complex array of antennae, like this Brindled Beauty, below?
Surely it would be an advantage to have the largest, most sensitive antennae possible? It appears that this would be the case, but there is a price to pay for having a huge array of pheromone detectors on your head. That price is flight efficiency. Complex bi-pectinate antennae are found on larger moths. Smaller, lighter moths cannot carry around complex antennae without compromising their flight efficiency. Larger moths are less abundant than smaller moths. This is why most moth species have simple filamentous antennae.
Digging deeper, it appears that even simple filamentous antennae have adapted to improve the efficiency of sex hormone detection. Simple filamentous antennae are covered in scales, which have a function in the detection of pheromones:
This paper found that the presence of these scales increased the amount of nanoparticles (like pheromones) around the antenna, and even filtered out microparticles (like dust), which further increased the efficiency of the antenna. In this way the simple filamentous antennae of smaller moths have become increasingly sensitive at detecting pheromones, without compromising flight efficiency.
The greater the detail you discover about the natural world, the greater the wonder it generates. The fact that complex pectinate arrays can make antennae look like giant ears is pretty cool too:
Pale Tussock
Devon 2: some moths
We took the moth trap on our family holiday to coastal South Devon in late August. We were staying on the side of a hill, backed by deciduous woodland, but with open coastal habitat nearby. We caught a decent selection of species, as far as our relative inexperience allows us to tell, though conditions were a bit cool and windy to be ideal.
Above, always a favourite, Burnished Brass. This individual left some gold dust on my daughter’s finger. Below, Poplar Hawk Moths were frequent. 
Hawk Moths are always a great way to engage children, our nieces loved seeing them. 
Above, our first Marbled Green. Below, the spectacular Jersey Tiger. We saw a few of these day-flying moths locally (photo by our eldest daughter): 
Below, Black Arches: fantastic antennae! 
Above, a Yellow-tail from the only angle you that can see the tail. Below, the wonderfully named Blood Vein (photo by our eldest daughter): 
Above, the common Lesser Broad-bordered Yellow Underwing. Long name, great eyes. There were also Four-spotted Footman and Rosy Footman (below): 
Each trap also attracted many Shield Bugs, much our daughter’s delight: 
Hummingbird Hawk Moths were very common. A Buddleia bush behind the house usually had a couple buzzing around feeding and we came across them in the village and even on the cliffs above the beach. 
One afternoon our youngest daughter came running to us with some news:
“Daddy, there is a Hummingbird Hawkmoth INSIDE THE HOUSE!” exclaimed my 6 year old. And there was. A fantastic opportunity to study this agile species up close, (check out those pupils), before a safe release 👍🏻@BritishMoths @savebutterflies @BCDevon @UpperThamesBC pic.twitter.com/QSG6pGL8lf
— Tom Bedford (@TomBedford12) August 22, 2018
A Hummingbird Hawk Moth had flown through an open window into the house. After much flying up against the windows it finally rested and I caught it in a glass and took it outside. I can’t recall ever seeing this species at rest before. The folded wings completely cover the orange hind-wing and the tail covers the black and white lower thorax. I slipped a piece of white paper under the jar to create a clean back ground for these pictures:
A further treat was bumping into a moth expert. Janet Cheney has just stepped down from being a regional coordinator for UK moth records. She was delighted that we had an interest in moths and kindly offered to come over on our last night and set up her mercury vapour (MV) bulb and moth trap on our patio. These bulbs are seriously bright: 
Below, a view of the village at night: on the far left, the moon; on the far right Janet’s MV bulb, clearly illuminating the surrounding trees and appearing brighter than the moon! The bulb’s reflection is also visible in the sea, bottom right: 
Janet came over the following morning and talked us though our catch. The cold, windy conditions were far from ideal for mothing, but Janet’s expertise and enthusiasm were inspiring. 
Below, Oak Eggar:
Yet another reminder that whilst the wildlife may be the focus of our interest, it is the great people that you meet and learn from along the way the way that is the real pleasure of the journey.
Emperor Moths, from egg to cocoon in 6 weeks
Earlier this year we were fortunate to be given some Emperor Moth eggs by Martin Wainwright, author of the excellent “Martin’s Moths” blog. I saw a blog post by Martin offering eggs and took him up on his offer. Martin used to be the northern editor of the Guardian and unbeknown to him, the Country Diary section of that newspaper was something of an influence on my early adolescent self. I would turn to the Country Diary page (yes children, imagine turning pages of paper to find something of interest!) to see if there were snippets of information or descriptions of bird life from around the UK. It was a brief wildlife moment in the chaos of a large family breakfast routine. I recently discovered that Martin has published a collection of writings from The Country Diary, “A Gleaming Landscape: 100 years of the Guardian’s Country Diary“. Martin helps publicise moths enthusiastically and can be said to have brought moths to the people! The Emperor Moth eggs he gave us were tiny and sat attached to the corner of an eggbox: 
Little happened for a few days and then on May 16th the eggs began to hatch. Below, the freshly emerged caterpillars having their first taste of Hawthorn leaves. The eggs are visible in the background:
The first caterpillars are nearly entirely black in colour. There is just a hint of green at the base of the hair nodules: 
We then embarked on a month of daily Hawthorn leaf gathering. Fortunately, Hawthorn is one of the most abundant trees:
The caterpillars grew very rapidly, but their skin can only stretch to a certain limit. After nearly two weeks, the first caterpillars (known as first instars) shed their skin to reveal a larger black and orange skin. These are the second instars, the second stage. Below, Emperor Moth caterpillar transformation from tiny black first instars to huge green fourth instars in the space of just over a month. My left thumbnail is being used to give some idea of scale: 
Below, a fourth instar Emperor Moth caterpillar emerges from it’s third instar skin: 
The fourth instar caterpillars were big beasts. After a month the tank was filled with alarmingly active, huge green, black and yellow caterpillars. We were now up to three feeds a day!
The largest caterpillars were between 6 and 7 cm in length:
Emperor Moths are related to silk moths. After 6 weeks some of the adults began spinning their cocoons: 
The silk that they produce is silvery white in colour at first. They gather twigs and leaves in around them: 
In the centre of the picture below, you can make out the head of the caterpillar through the hole in the top of the cocoon: 
The silk then dries and ends up being a gingery colour. It sets as hard as steel. The caterpillars will spend the rest of the summer and all winter in their cocoon, before they emerge in April as adult moths. The energy that they derived from the Hawthorn leaves will sustain them all winter and for all of the adult life of the Emperor Moth. The adult moths do not feed. Their purpose is to emerge and mate and then they die. The moths (and butterflies) that we see on the wing are only the brief final adult stage of an insect species that spends far longer as a caterpillar and as a pupae, sometimes in a cocoon, depending on the species. In April 2019 we await the delight of the adults emerging, although Martin mentioned that sometimes they may skip a year and emerge two years after they have pupated. Emperor Moths are fantastic, large, beautifully marked moths. The larger females emit pheromones, attracting the males (below) with scent. And then it all begins again: mating, eggs, caterpillars and cocoons.
[image © www.ukmoths.org.uk]
Many thanks to Martin for his generosity and enthusiasm in our Emperor Moth project.
Lime Hawkmoth
Another day, another long anticipated Hawkmoth! After our first Privet Hawkmoth two days ago, this morning’s treat was a vision of stylish pink and green, a beautiful Lime Hawkmoth: 
The head pattern is a cool, green and stripey:
Glorious greens:
Two new Hawkmoth species in three days. Which new Hawkmoth species will be next?
Also-rans today included 2 Large Elephant Hawkmoths, our first Marbled White Spot and the return of the small, but delicately marked Spindle Ermine: 
Hot moths
There is nothing like a heat wave to bring the moths out, even in suburban Headington. It had already been a busy morning, and in amongst the Scarlet Tigers, Hearts and Darts and Common Footmen was our first Lackey Moth:
…our first Twenty-plume Moth:
…and not one, but two, Large Elephant Hawk Moths:
Then my youngest daughter noticed a long, dark shape the size of a small aircraft in the moth trap:
At last a Privet Hawk Moth had visited our garden! It was an absolute beast. The eye is enormous: 
The black back and face are separated by a wide light grey go-faster stripe that wraps around the head:
This is Britain’s largest resident moth, it dwarfed the Large Elephant Hawk Moths: 
The pink and black body becomes visible as it spreads it’s wings:
Wing detail:
A source of much pre-breakfast joy, we were delighted to admire this stunning garden visitor: 
A sudden influx of elephants
Last weekend we were treated to some colour in the moth trap. Two nights in Wokingham (Berkshire) produced our first Small Elephant Hawk Moth. It was a rather worn individual:
Hawkmoths were the order of the night. We have still yet to find a Poplar Hawk Moth in the trap, but fortunately one appeared in a bedroom on our first morning!
They are fabulous beasts that repay close study:
Is there a grumpier looking moth?
Wing detail:
With Small Elephant Hawk Moth for size comparison:
The second morning produced a Large Elephant Hawk Moth, the bigger stripier relative of Small Elephant: 
There was also a brace of Buff-tips, the broken twig of the moth world and still one of my favourite moths (more here also): 
Spot the real broken branch:
Back in Oxford, the pink theme continued with another Large Elephant Hawk Moth, this time in our Headington garden. It was briefly photo-bombed by a Bumblebee:
Buff-tip
We took the moth trap when we stayed in Wokingham, Berkshire, last night:
That moment when you realise that you’ve just found your first Buff-tip!
This is a moth that repays study from every angle, a silver birch twig in living form: 
Another surprise in the moth trap was this Stag Beetle. It is sadly unusual to come across Stag Beetles these days, even in areas like this where they were common 20 years ago:
