Anyone in Britain seen a map lately?

Has anyone in Britain seen a map lately? Clouded yellows — two a penny. Swallowtails — already plenty of sightings along the South Coast. But a map, now that would be something.

Map

Map of France, from Burgundy actually.

The European map butterfly, Araschnia levana, is named for its prettily marked underside with its criss-cross of white lines supposedly resembling the radiating compass marks superimposed on old maps and nautical charts. It’s common enough on the Continent, and occurs through much of France, where this picture was taken a few years ago. What’s more, its caterpillars feed on the ubiquitous stinging nettle and it has been spreading through Europe, having extended its range hundreds of kilometres further north and west during the last few decades. It’ll be here any day now.

The weird thing about this butterfly is that it has two strikingly different colour forms on the upper surface. The spring butterflies, emerging from overwintered chrysalides, are bright orange on the upperside, patterned with a series of black spots and blotches — form levana. These lay eggs and the caterpillars feed through the summer, pupate, and emerge a few weeks later. The late-summer emergers are jet black above, with a strong white flash down each wing — form prorsa. There are plenty of galleries available to look at, here and here, for example.

Its possible that when the butterfly finally gets here it may only have one generation a year, as it does in northern parts of its range, and up mountains; this would be the chrsalis-overwintering orange form levana.

The map already has a tenuous claim in Britain, because 100 years ago it was established in the Forest of Dean. The story goes that it was deliberately released by some well-meaning, but ill-informed enthusiast around 1912. The tale continues that a less enthusiastic entomologist, one A.B Farn, was so incensed at this foreign transgressor that in 1915 he vowed to exterminate it by destroying every individual he could find. It seems unlikely that one butterfly maniac could eradicate a thriving colony; much more likely that this insect was floundering anyway, well away from its comfort zone in central Europe.

Today things are different and as that comfort zone appears to be expanding northwards, colonization of Britain now seems inevitable.

The working copy

Some time during the late 1940s and early 50s my father’s burgeoning interest in natural history embraced flies. However, hampered by lack of a microscope and books, his options were limited. He wrote to eminent dipterist Leonard Parmenter and was pleased to be invited to his house. Parmenter was helpful and encouraging and although Dad was mainly a botanist, a few of his published articles were on hoverflies.
Just as today, the Syrphidae offered a good introduction to flies, many of which other groups offer taxonomic difficulties that still give experts nightmares. They are generally large, bright, attractive and distinctive species, and there was a good ID guide available.
At that time the masterful monograph on the hoverflies, by the great George Verrall, was the most important book on the group, but it was huge, at over 800 pages, and was an expensive purchase beyond my father’s meagre means.
Instead, over a period of several months, he borrowed a copy of the book from Paddington (I think) public library and laboriously copied out various parts of it longhand into three large ruled hardback exercise books, pictures and all. This he used to identify and research the flies.
Years later he was able to get hold of the 1969 facsimile reprint of Verrall’s book, still quite an expensive book even then, but he kept his manuscript copy, now a poignant memento of an earlier time.

A proof-louse

It stands to reason that a head-louse lives on heads, a plant-louse lives on plants, a bark-louse lives on tree trunks, so a proof-louse occurs on proofs.

Hopefully not a sign of a lousy book.

Hopefully not a sign of a lousy book.

This is what crawled over the photocopy proofs of House Guests, House Pests whilst I was reading through them on holiday last week. It’s one of the book/bark/flour lice (order Psocoptera), something like Liposcelis which is often found damaging paper, or in stored food. We have them living in various cupboards in the kitchen and that’s probably where this one came from originally.

However, it had been on a long journey, because it crawled out of the proofs in Strobl, in the Austrian Alps, after I took them from the brown envelop that I had been carrying in my small hand-luggage back-pack.

I suspect my bag, long used on family trips to hold packed lunches, savoury snacks, sweets, and various other food items frequently spilled, has its own internal ecosystem and that there is actually a thriving colony of Liposcelis living at the bottom of it.

I’ll give it a bit of a shake-out before I use it next.

 

Snatched from the jaws of death

That’s not always the optimistic line it’s made out to be. Sadly, for this moth, they were the jaws of a dragonfly, and the moth was already dead.

The emperor dragonfly, Anax imperator, is a large and dramatic insect on any occasion, but when one rattled past my face with a huge moth in its mouth it was particularly startling. I tried to creep up on it for a photo, when it came to rest on a bramble leaf, but I was squelching near ankle deep in muddy water and pushing my way through waist high rushes so my approach was not gentle and I disturbed the poor beast. It dropped the moth, but got its meal, since most of the highly nutritious moth body was missing.

Even from the damaged and worn remains I can tell this is a male gypsy moth, Lymantria dispar. Hmmm. Despite the name being used positively for an acrobatic biplane and Sir Francis Chichester’s round-the-world yacht, the gypsy moth of the insect world is a notifiable forestry pest, so how do I break the news to the ecological wardens of London’s Olympic Park that they might have an infestation on their hands?

Unfortunately a lone male doesn’t tell us much. They migrate far and even before genuine breeding colonies were discovered in the London area they turned up irregularly in southern England.

There are infestations of gypsy moth in several parts of London, so another in the Olympic Park would be no surprise. The gardening staff will have to keep an eye out for the gregarious caterpillar masses.

In the mean time let’s hope that the park’s healthy population of large dragonflies can continue their biocontrol efforts.

This bee broke my Dad’s arm

On 30 March 1980 my father picked me up from my student flat in Brighton and we headed off to the old sand pit in Rewell Wood near Arundel West Sussex. It was a fine day and the disused quarry promised some unusual early spring bees and wasps, just starting their nest burrows in the scrubby but still sun-exposed vertical sand faces.
Dad and I often met up like this, a chance for father/son wanderings together in the Weald or across the South Downs of Sussex. As usual I’d mainly be looking at insects and he’d also be recording plants, but the sand pit, at the start of our countryside ramble, offered common interest in the Hymenoptera.
We hadn’t been there long, however, when Dad came over to me looking slightly sheepish. He’d tripped whilst trying to net a bee, and hurt his shoulder. He wasn’t in excruciating pain, but complained of discomfort in his upper left arm. What to do?
He was unable to drive with only one arm, but the thought of calling an ambulance only added to his embarrassment. So I set off the country mile to the pub at the next road junction to phone a friend.
We knew Mike Edwards, who lived in Midhurst, slightly. I’m not sure we’d ever been to each other’s houses, but had met him at entomological meetings on and off. He was the nearest help I knew. I made the call from the coin-operated phone on the bar. And amazingly he was in. He would rush out immediately.
Half an hour later he was there to pick up me and Dad and we headed off to Midhurst A&E. Despite a town fair completely blocking the streets with traffic, Mike negotiated inconvenient pavements and oncoming traffic as he drove down the wrong side of the road. By noon we were in the waiting room as Dad explained, trying to keep a straight face, that he had taken a tumble chasing after a bee.
He’d cracked his upper arm bone, his humerus, ha ha very amusing. No plaster was necessary, but arm in a sling for a month, and how to get back to our homes?
I can never thank Mike Edwards enough. He rounded up fellow local entomologist Chris Haes and we headed back to Rewell Wood to collect our abandoned motor. Mike would drive Dad to Newhaven, Chris would drive Dad’s car with me navigating. Having dropped off Mr Invalid, they then drove all the way back into deepest West Sussex, dropping me off in Brighton on their way through.
Sorting out some of Dad’s things I thought I’d try and find that bee. Sure enough, there it is in the catalogue against specimen number 3879: “Flying in gravel pit, Rewell Wood, Tortington, 30.3.80, female Andrena clerkella. P.S. Caused a broken arm.”

Less is more, or small is beautiful, but certainly two is a colony

It’s the little things that get me excited. Take this tiny (4 mm) longhorn beetle, Nathrius brevipennis. The longhorns are a diverse group of beetles, but most of them are relatively large (some UK species to 50 mm not including the long antennae) and others are brightly coloured. Nathrius must rank as our smallest and dullest.

Nathrius brevipennis is too small to have an English name, but at 4 mm I'm thinking "short longhorn".

Nathrius brevipennis is too small to have an English name, but at 4 mm I’m thinking “short longhorn”.

But when this one crawled over my small garden table on Monday (14 July) I nearly fell off my chair. Nathrius, I knew, is very rare; so rare, in fact, that it is barely regarded as being British at all. Some of the older books do not include it, some others say “naturalized”. Occasionally specimens emerge from decorative twigs of uncertain provenance bought in florist shops, others chew their way out of wicker baskets imported from who knows where. Records in genuine outdoor habitats, in the wild, are scant.

My Nathrius is special, not because it is so rare, or even because I found it out of doors, but because it is the second specimen I have found out of doors in my garden. The first specimen crawled over my arm as I sat outside reading the newspaper on 18 July 2010. Of course I enthusiastically reported its presence in the entomological press here.

So, two specimens in 4 years makes my garden the largest known UK colony of this small but fascinating insect.

Ivydale’s inse(c)t day

It was the obvious wordplay, so I went with it. They were always called insect days in our house. Inset? what on Earth does that mean anyway? At least ‘teacher training day’ makes some sort of sense.

This way; past stinging nettles, trailing brambles, and mud.

This way; past stinging nettles, trailing brambles, and mud.

I didn’t call it a bug-hunt though (too demeaning for adults) so we indulged in the citizen science that is the bioblitz. But it was a bug hunt really. The hunters were armed with empty humous pots and sent off to see what could be scooped from the herbage of One Tree Hill off Brenchley Gardens.

I’d set up a trestle table and microscope in the small grassy clearing half way up the hill and along everyone came.

Ready to rumble.

Ready to rumble.

Not surprisingly the list of just over 60 species was really quite modest. The site we investigated was very restricted, barely a few hundred square metres of secondary woodland edge and irregularly mown grass and bramble thicket.

Nevertheless everyone seemed very enthusiastic. (Well, I did get a couple of sit-outs “Oooh, I don’t do insects”, slightly disappointing.) There were five species of bumble, including the tree bumblebee, Bombus hypnorum, and one of the cuckoo bumblebees, Bombus vestalis.

The most unusual find of the day was a single small (5.5 mm) metallic green jewel beetle. Agrilus laticornis is notionally ‘nationally scarce’, a denizen of oak woodland (there were some oaks growing here) where its larvae burrow through the bark of dead trunks and branches. It’s always a nice thing to find.

Agrilus laticornis, confirmed by examination of the shape of the prosternal plate behind the front coxae.

Agrilus laticornis, confirmed by examination of the shape of the prosternal plate behind the front coxae. Technical terms obligatory here folks.

One thing, though, became immediately clear — although older, wiser and potentially better informed, the adults could not compete with the keen and crisp eye-sight of their 5- to 12-year-old pupils. Also, being shorter, the children are naturally closer to the ground, always a useful thing when bug-hunting.