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.

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Case study: 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.

Butterfly recording form

Butterfly recording form

Butterfly recording form

Butterfly recording form

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

Verify

Expert verifiers 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.

Butterfly records management system

Butterfly record verification

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

Butterfly records management system

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.

Butterfly data: archive

Butterfly data: archive

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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.

Nationally 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 we publish an interactive ‘White Holes’ map on the branch website, which combines data from the national database with more up-to-date 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 made available.

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.

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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.

Fifth instar puss moth larva

5th instar puss moth larva. All the outlandish features of the mature larvae are now present, including the lurid pink face, flagellae and false eye spots.

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.

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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

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Spring Wood Ant Antics

Wood ant with heather seed

Wood ant (Formica rufa) foraging in early spring

The wood ant mounds among the pine trees were beginning to stir on my visit to the RSPB’s Arne reserve in Dorset recently.

Nests become active in early spring when worker ants begin to forage for food items and building materials to repair damage sustained over the winter months. Badgers, magpies, jays and other animals often raid wood ant nests for food.

Wood ant carrying twig

Wood ants are capable of carrying relatively heavy loads

Wood ant colonies can contain up to half a million individuals. On sunny days worker ants ‘sunbathe’ at the nest entrance to absorb heat and then re-enter the nest to release it – keeping it at a steady temperature. When the nest becomes too warm they open small vents to cool it down.

Wood ants at nest entrance

Sunbathing worker ants at nest entrance

The ants are particularly aggressive in springtime as they re-define their territories. Sometimes ants from weaker neighbouring colonies are recruited by force and carried back to the main colony.

Worker ant carrying another wood ant between nests

This species of wood ant is classified as Near Threatened (NT) in the IUCN Red List and classified in Great Britain as Local. Numbers seem to be increasing in the south of England but it has become locally extinct in parts of its former range in the north and east of England, the Midlands and north Wales.

Photographing ants is always a challenge because they’re small and they move very fast. It’s a good idea to keep your trousers tucked firmly into your socks when lying on the ground this close to a nest full of them! They will bite occasionally but can’t pierce skin. The formic acid they squirt in defence is too weak to harm humans.