White Admiral Watch

White Admiral butterfly metamorphosis: from larva to prepupa to pupa to imago.

In Sussex during the COVID-19 epidemic of 2020 I followed one spectacular White Admiral butterfly through pupation to emergence

The White Admiral (Limenitis camilla) is a large woodland butterfly which glides effortlessly along forest rides. Its numbers in the UK have rebounded since the First World War, possibly due to the cessation of coppicing which, unusually, has benefited this species since its larvae require Honeysuckle growing in shady woodland.

28 May

My first, long awaited, encounter with ‘Camilla’ came on 28 May when my many searches of Honeysuckle vines finally bore fruit and this magnificent creature suddenly greeted me.

White Admiral (Limenitis camilla) 5th instar caterpillar on honeysuckle (Lonicera periclymenum).

White Admiral caterpillars are entirely dependent on Honeysuckle for their survival, feeding on its leaves through all five larval instars and hibernating within their folds.

At more than 2 cm in length this was a fifth and final stage caterpillar, exotic in appearance compared to the majority of British butterfly larvae, adorned with branching red spines along its back and resting in a raised serpentine position.

31 May

When I returned 3 days later Camilla was already preparing to pupate, hanging beneath a Honeysuckle leaf, suspended from her hind claspers attached to a pad of silk.

White admiral (Limenitis camilla) prepupa suspended from honeysuckle (Lonicera periclymenum).

2 June

48 hours later the pupa was now fully formed, with two prominent horns on the head and an odd protrusion further back.

“The pupa bears a close resemblance to a profile portrait of Punch.”

– Frohawk (1924)

White admiral (Limenitis camilla) pupa suspended from honeysuckle (Lonicera periclymenum). Day 1.

7 June

The pupa darkened up a little in the next few days, its undulations mimicking the Honeysuckle leaves quite convincingly.

White admiral (Limenitis camilla) pupa suspended from honeysuckle (Lonicera periclymenum). Day 6.

For the next two weeks few visible changes occurred and the weather turned cold and wet. A marauding army of small birds came and went, leaving Camilla thankfully undisturbed.

23 June

Around Day 22 the folded wing veins became a bit more pronounced beneath the pupal case and its body seemed to have plumped up a bit. Warm, sunny weather had returned to the woodland glade.

White admiral (Limenitis camilla) pupa suspended from honeysuckle (Lonicera periclymenum). Day 22.

24 June

Revisiting on the morning of Day 23 I found Camilla had darkened up overnight, turning from green to brown, signalling that ‘eclosion’ of the adult butterfly was imminent.

White admiral (Limenitis camilla) pupa suspended from honeysuckle (Lonicera periclymenum). Day 23 (AM).

By 5pm that afternoon my ‘White’ Admiral was now distinctly black!

White admiral (Limenitis camilla) pupa suspended from honeysuckle (Lonicera periclymenum). Day 23 (PM).

From a different angle the butterfly’s wing structure and patternation could clearly be seen.

“Before emergence it turns to a bronze-black all over, losing almost all the metallic lustre of silver-gilt; the white wing markings of the imago show pale amber colour through the pupal skin.”

– Frohawk (1924)

White admiral (Limenitis camilla) pupa suspended from honeysuckle (Lonicera periclymenum). Day 23 (PM).

I was hopeful the adult butterfly would emerge that evening and so remained until well after dusk, but as it grew dark I was forced to return home for the night.

25 June

Back on site very early next morning I was relieved to discover that the big moment had yet to arrive.

Camilla remained suspended from the Honeysuckle leaf until 09:11 on Day 24 when she suddenly popped out of her chrysalis in the blink of an eye, annoyingly while my back was briefly turned!

White admiral (Limenitis camilla) imago newly hatched. Day 24.

Camilla luxuriated in the warm morning sunlight streaming through the oak canopy, slowly expanding her glorious wings as she clung to the vacant ‘exuvia’.

White admiral (Limenitis camilla) imago newly hatched. Day 24.

By 10:50 her wings were fully expanded and at 11:12, two hours after emergence, she clambered nimbly up onto the Honeysuckle leaf which had supported her pupa through sun and rain, heat and cold, for the past 24 days. It would now become her launching pad.

White admiral (Limenitis camilla) imago shortly before first flight.

And then 8 minutes later, at 11:20 she flew for the first time… and was gone!

Video showing newly emerged White Admiral (Limenitis camilla) butterfly drying its wings before takeoff.

Except that I strongly suspect she hung around…

I only witnessed one other adult White Admiral in the wood that summer. The individual photographed below frequented Bramble blossom within metres of Camilla’s hatching site, sunning itself on the woodland floor nearby and alighting on Honeysuckle, likely assessing suitable spots to lay her eggs for the next generation of White Admiral caterpillars to emerge.

White admiral (Limenitis camilla) butterfly nectaring on bramble flowers.

To be continued…

Related links

Toads on roads

Common toad (Bufo bufo) crossing a road at night on migration to breeding pond. Sussex, UK.

After emerging from hibernation in early spring common toads (Bufo bufo) migrate back to their breeding ponds at night. Sometimes this involves crossing busy roads and many toads are sadly hit and killed by passing cars.

Each year volunteers working with charities such as Froglife and local Amphibian and Reptile Groups attempt to ferry migrating toads, frogs and newts to safety at known crossing points.

Toad crossing signage. Sussex, UK.
Common toad (Bufo bufo) juvenile recovered at road crossing on spring migration. Surrey, UK.
Toads retrieved from road in a bucket

Male toads grasp females in a position known as ‘amplexus’ as they attempt to fertilise her eggs. Often a mating pair can be found together before they reach the nearest pond. When this happens males hitch a free ride!

Common toads in amplexus while crossing a road on spring migration

Related links

Inside flies

I was delighted to see my work featured in Erica McAlister’s new book on diptera: ‘The Inside Out of Flies’, published by London’s Natural History Museum last month.

Cover of book on flies
The Inside Out of Flies by Erica McAlister

The photograph in question shows hundreds of eggs laid by a member of the horse fly family (Tabanidae).

Horse fly eggs featured in The Inside Out of Flies

Erica uses the reproductive strategy of horse flies to illustrate r/K selection theory:

r-selected species are seen as more opportunistic and are able to propogate more quickly if the environment is suitable, whereas K-strategists spend more time investing in a few offspring to give them whatever competitive advantages they can to prosper in what are often already crowded niches

The original image from my archive is shown below:

Horse fly eggs (Tabanus cordiger?) on salad burnet (Sanguisorba minor) stem. Surrey, UK

Related links

Purbeck mason wasp

In the UK the rare Purbeck mason wasp (Pseudepipona herrichii) is found only in the Isle of Purbeck, Dorset.

The female excavates a nest burrow in bare ground on heathland and later seals it with moistened clay.

Wasp with excavated soil

Purbeck mason wasp (Pseudepipona herrichii) excavating nest burrow on heathland. Dorset, UK.

She stocks her burrow with the larvae of a small moth which feeds mainly on bell heather.

Purbeck mason wasp: prey

Purbeck mason wasp (Pseudepipona herrichii) with Acleris hyemana moth larva prey at nest burrow entrance. Dorset, UK.

The adults chew distinctive holes in the heather flowers to obtain nectar which their short tongues could not otherwise reach.

Wasp drinking from heather

Purbeck mason wasp male nectaring on bell heather. Dorset, UK.

The Purbeck mason wasp is thought to rely solely on the larvae of Acleris hyemna, but in 2017 I photographed this female provisioning her nest with what appears to be the moth Acleris notana.

Purbeck mason wasp: prey

Purbeck mason wasp (Pseudepipona herrichii) with moth larva prey (Acleris notana?) at nest burrow entrance. Dorset, UK.

One small victory for citizen science?

Related links

Fly orchid pollinator

The fly orchid (Ophrys insectifera) is usually found on chalk and limestone soils in open deciduous woodland and scrub, but is also recorded from grassland and chalk-pits. It is rare in the UK and even at known locations can be difficult to spot.

Fly orchids

Fly orchids in woodland clearing. Surrey, UK.

Fly orchids are in flower between May and June. At this time they attract male digger wasps (Argogorytes mystaceus) with a scent which closely resembles the female wasp’s pheromone.

Males attempt to copulate with the orchid and during this process pollinia become attached, which may be carried to the stigma of another flower, completing pollination.

Digger wasp pseudo-copulating with fly orchid

Digger wasp attracted to fly orchid flower.

Male digger wasp pseudo-copulating with fly orchid

Male digger wasp pseudo-copulating with fly orchid.

Digger wasp with fly orchid pollinia

Fly orchid pollinia attached to the head of male digger wasp.

I was finally lucky enough to observe and document this behaviour in the Surrey Hills earlier this year.

Find out more

Butterfly Conservation

Working for the local branch of Butterfly Conservation I developed an online system to document sightings of butterflies submitted by members of the public in Dorset.

This ‘citizen science’ project encourages engagement in nature conservation and adds to our knowledge of these vital environmental indicator species.

In 2018 more than 44,000 butterflies were successfully recorded using this method.

Capture

Initially butterfly spotters are directed to a web form which collects personal info, location details including grid reference, and species observed.

dbc-recording-form-01

Butterfly recording form: recorder info

Butterfly recording form: site details

Butterfly recording form: site details

This information is then inserted into the Dorset Branch web sightings database.

Verify

Local experts are given password-protected access to a record management interface on the branch website. Recently submitted butterfly sightings can be reviewed and verified with a single click.

dbc-recording-verify-01

Butterfly record verification

Questionable records can be studied in more detail and recorders contacted to clarify information as necessary.

Butterfly record management view

Butterfly record management view

Interpret

Verified records are instantly published to the branch website, using a number of graphical representations for easy interpretation.

Butterfly data: map

Butterfly data: map

Butterfly data: tree chart

Butterfly data: tree chart

Butterfly data: calendar

Butterfly data: calendar

Butterfly data: bar chart

Butterfly data: bar chart

Butterfly data: pie chart

Butterfly data: pie chart

Butterfly data: Gantt chart

Butterfly data: Gantt chart

Archive

Butterfly sightings received via the website are archived online for the public to explore in greater depth.

dbc-recording-archive

Butterfly data: archive

Share

Casual sightings received via the branch website provide a useful snapshot of butterfly activity in Dorset. But for research purposes it’s necessary to combine them with data from formally structured butterfly transects and other recording schemes within the region and nationally.

Website data is exported to the national society’s database annually. National butterfly recording cycles run for 5 years, at the end of which an ‘atlas’ is produced, showing the updated distribution of species and population trends.

To encourage recording in under-represented areas an interactive ‘White Holes’ map is published on the branch website. This combines data from the national database with more up-to-date regional web sightings.

Butterfly data: White Holes map

Butterfly data: White Holes map

Butterfly data: White Holes map detail

Butterfly data: White Holes map detail

It’s possible to use this map on a GPS-enabled mobile device to locate the nearest White Hole for observation. A list of previously recorded species for each 1km square is also presented.

Over the past 4 years this recording system has gathered more than 180,000 individual butterfly records, contributing to our understanding of these beautiful creatures and the changing environment they inhabit.

Oak Galls: Wasp vs. Plant

Oak trees are home to more than 30 species of gall wasp. The larval stage of these insects induce the plant to produce abnormal growths, known as galls, which enclose and protect them as they develop.

Oak gall wasp larva IV

Galls come in a variety of fantastical shapes, each unique to particular species.

Oak marble gall

Marble galls

Hard woody spherical galls up to 25mm in diameter on the oak stems. Initially green but later become brown.

Created by: Andricus kollari

Oak apple gall

Oak Apple Gall II

These galls have a spongy texture and are brownish white, tinged with pink.

Created by: Biorhiza pallida

Common spangle gall

Common Spangle Galls II

Yellowish gingery brown disc-shaped galls on the underside of oak leaves in late summer and early autumn.

Created by: Neuroterus quercusbaccarum

Silk button spangle gall

Silk Button Surfeit

Golden brown discs with a depressed centre on the underside of oak leaves in late summer through to early autumn.

Created by: Neuroterus numismalis

Knopper gall

Knopper gall

The acorn becomes a ridged woody structure. The gall is initially yellowish green and sticky but later greyish brown.

Created by: Andricus quercuscalicis

Cherry gall

Oak Cherry Galls

Yellowish green or red spherical galls up to 20mm in diameter on the underside of oak leaves in late summer and autumn.

Created by: Cynips quercusfolii

It gets complicated…

Oak gall wasps have complex life cycles, with alternating generations that are either sexual with males and females, or asexual with females only.

The two generations of wasp often produce different types of gall on different parts of the tree, and in some species the two generations alternate between native and non-native species of oak.

Oak Gall Wasps VI

There are also wasps which specialise in injecting their eggs into oak galls. Their larvae then eat the resident eggs or larvae before they emerge.

Chalcid Wasp

The example above shows a type of Chalcid wasp investigating a fresh oak marble gall.

Find out more

Puss Moth Metamorphosis

I’ve photographed puss moth caterpillars (Cerura vinula) before, but this summer I wanted to follow them through all 5 stages, or ‘instars’, of their larval development.

Luckily I discovered a batch of recently laid puss moth eggs by searching the exact same aspen sapling chosen by another adult female the previous year.

6 June: Unhatched Ova

Puss moth eggs (Cerura vinula) on aspen
Cluster of puss moth eggs (Cerura vinula) on underside of aspen leaf

12 June: Hatched Ova

Hatched eggs of puss moth larvae (Cerura vinula)
Hatched eggs of puss moth larvae (Cerura vinula), showing signs of early feeding activity nearby.

12 June: 1st Instar

The ‘puss’ moths look a lot more cat-like at this early stage in their development I reckon.

First instar puss moth larva (Cerura vinula) on aspen leaf
1st instar puss moth larva (Cerura vinula) on aspen leaf. The distinctive tail-like appendages are already present.
1st instar puss moth siblings (Cerura vinula) feeding on aspen
1st instar puss moth siblings (Cerura vinula) feeding on aspen

15 June: 2nd Instar

I’d received a shock on my visit the previous day when I found the caterpillars frozen rigid in position, with their backs arched and tails in the air. They looked decidedly dead and I thought they must have been parasitised. Today, however, they were re-animated once more.

Puss moth siblings sharing the same aspen leaf
Puss moth siblings sharing the same aspen leaf
Puss moth siblings on shared aspen leaf
The puss moth siblings were running out of space on their steadily consumed leaf and occasionally paused to whip their tails furiously at each other.
Second instar puss moth larva on aspen leaf
Close-up of 2nd instar puss moth. The jagged tentacles above the head are very prominent at this stage, unlike in the fully mature larva.

24 June: 3rd Instar

9 days later, after vanishing for several days, the two siblings had relocated further up the branch they originally hatched on. Neither was particularly active in the midday heat.

Third instar puss moth larva resting on silk pad
3rd instar puss moth larva resting on silk pad
Third instar puss moth larva resting on silk pad on aspen leaf
The distinctive saddle patterning of the puss moth caterpillar is much more visible by this stage.

28 June: 4th Instar

It lashed with rain on my next visit and the only visible puss moth was trying its hardest not to get pummeled off the leaf. Its silk pad lashed to the surface provides a firm anchor for feet to grasp.

4th instar puss moth on aspen leaf
4th instar puss moth clinging to wet aspen leaf. The hump on its back is now filling out.
4th instar puss moth larva
At this stage in its development the puss moth’s body has begun to envelop its head and the tentacles appear to have retracted.

9 July: 5th Instar

A further 11 days later I returned to find only one of the original 4 puss moth siblings remaining, now in its magnificent mature larval form.

Puss moth larva (Cerura vinula) 5th instar in defensive posture.
Fifth instar puss moth larva detail showing extended pink flagellae
Detail showing extended pink flagellae. When threatened the puss moth extends these whip-like appendages from its tail end and waves them around crazily.

To be continued…

Soon after reaching this mature larval stage the puss moth stops eating and leaves in search of a safe place to pupate. Its transformation into the furry white adult moth can then begin. Despite much searching I couldn’t locate any pupae. Next time maybe!

Related links:

WPOTY 2014: Shortlisted

Another year, another shortlisted image! This time in the ‘Invertebrates’ category:

Pond skaters

River sprites

Canon 600D + 100-400mm f/4.5-5.6L IS USM lens; 2 sec @ f/40; ISO 100

This is a long exposure image of pond skaters (Gerris sp.) in motion, taken in the shady bend of a local river one summer afternoon. Shortly after this frame was captured my tripod toppled over and the camera went for an expensive swim!

Unfortunately this year’s entry again failed to make the final cut. Congratulations to The Winners.

Related links:

Amphibian Kama Sutra

Common toads in amplexus

Common toads (Bufo bufo) spawning

After emerging from hibernation in early spring, toads migrate back to their breeding ponds.

Males fight to secure mates and often outnumber the females at some sites. When this happens the female may be grasped by several males in a position known as ‘amplexus’, as they compete to be in the best position to fertilise her eggs.

Common toads in amplexus

Group of toads in amplexus

Common toads in amplexus

Spawning might look fun but can also be life-threatening!

Common toads in amplexus

Toad sex is apparently a moveable feast!

The common toad is widespread in Surrey, however populations appear to be declining. Where toad migration routes cross busy roads there can be many fatalities, and local conservation groups police ‘Toad Crossings’ at dusk to help them safely across.

Common toad crossing track

This toad was late to the party, but managed to avoid oncoming traffic

Related links: