Wimbledon Common BioBlitz
Sunday 24th June 2018
On a pleasant summer weekend, Quekett members attended the fifth BioBlitz on Wimbledon Common (a Site of Special Scientific Interest (SSSI) and a Special Area of Conservation (SAC)) in south-west London as part of the Club’s microscopy outreach programme.
On Sunday 24th, Barry Wendon, Dennis Fullwood, Neil Henry and Paul Smith set up their microscopes and cameras in the Information Centre (next to the Ranger’s Office) to assist with identifying plants, insects and other organisms found during the organised walks. To get us started, we collected insects from plants on the Common and material from Queensmere, and Dennis set out some yellow pan traps.
Neil Henry used a PZO monocular microscope with the eyepiece replaced by a YW5.OM camera connected to a laptop with ToupView software, and found several interesting specimens from Queensmere.
Paul Smith used his Philip Harris stereomicroscope to sort material for a closer look under his Wild M11 compound microscope with gliding stage. To take photographs, Paul used his Canon EOS M mirrorless camera with a Canon EF 50mm f/1.8 lens (an afocal arrangement) attached to a television.
In the samples that Alan Wood collected from Hookhamslade Pond, Paul found starter colonies and larger structures of Cladophora, a reticulated filamentous green algae. These are interesting, but not the cause of the surface film.
Starter colony of Cladophora [by Paul Smith]
Filaments of Cladophora [by Paul Smith]
Dennis Fullwood used his Chinese inspection camera attached to a monitor to show insects collected from the Common.
Image of a click beetle (Selatosomus aeneus (L.)) from a Chinese inspection camera
Dennis also brought his Olymus SZ4045 stereomicroscope to show insects preserved in Baltic amber (not from the Common!) and other specimens.
Baltic amber under an Olympus stereomicroscope
Dennis set out yellow pan traps for insects. The yellow colour attracts some insects and they become trapped in water to which a drop of washing-up liquid has been added. A common lizard (Zootoca vivipara) found its way into one of the traps.
Yellow pan trap for catching insects
Dennis spent a long time with a youngster whose parents had recently bought him his first microscope, explaining how to adjust it to suit his eyes, how to focus, and how to use the built-in reflected and transmitted illumination. Fortunately, the microscope was very suitable for a youngster, a stereomicroscope from Brunel Microscopes. Stereomicroscopes provide a long working distance, specimens do not need to be prepared, and the relatively low magnification makes it easy to understand what you are looking at.
Dennis also brought his Nikon Labophot compound microscope and two large stand-mounted lenses with ring illuminators.
Visitors in the Information Centre included a Police Officer who now intends to buy one of the Chinese video inspection cameras and hopes to come to our Annual Exhibition on 6th October.
This year, Hookhamslade pond is almost covered by an unusual surface film (it is not oil, blanketweed or duckweed) and Quekett members have been asked to use their microscopes to try to identify it.
Scum-covered surface of Hookhamslade Pond
Butterfly and Dragonfly Walk
On Saturday 23rd, Alan Wood and Thanya Nirantasook joined the butterfly and dragonfly walk led by Bill Budd (dragonflies) and Martin Brown (butterflies). Peter Hirsch (new Conservator) and Nathalie Chevallier-Hean (Wimbledon Common Nature Club) were among the group that walked around the grassy plain, areas of woodland and two ponds.
We saw lots of interesting specimens and we were able to get close enough to some butterflies and damselflies to identify them and photograph them. We also saw several dragonflies, but they didn’t come close and only those with binoculars got a good look at them.
Watching dragonflies at Hookhamslade Pond
Watching an emerald damselfly at Bluegates Pond
Comma butterfly (Polygonia c-album (L.))
Small skipper butterfly (Thymelicus sylvestris (Poda))
Large skipper butterfly (Ochlanus sylvanus (Esper))
Ringlet butterfly (Aphantopus hyperantus (L.)) on bramble
Small heath butterfly (Coenonympha pamphilus (L.)) on tormentil
We found a dead small heath, and here is a close-up of its eye-spot:
Eye-spot of small heath butterfly (1.2 × 1 mm)
Blue-tailed damselfly (Ischnura elegans (Vander Linden))
Emerald damselfly (Lestes sponsa (Hansemann))
We also saw several Canada geese and a pair of coots with 2 large chicks on Bluegates Pond, and a pair of moorhens with 2 small chicks on Hookhamslade Pond.
Coot on Bluegates Pond
We also saw 2 nests of the invasive oak processionary moth (Thaumetopoea processionea (L.)) in oak trees.
Webbed nest of oak processionary caterpillars
In the evening of Saturday 23rd, Les Evans-Hill of Butterfly Conservation set out a moth trap with a mercury vapour lamp, and he brought it in the following morning. Several adults and children crowded round to watch Les carefully remove the egg trays and identify the moths.
Opening the moth trap
Moths on egg trays
There were dozens of different species, and here are photographs of 4 of the larger ones:
Small elephant hawk-moth (Deilephila porcellus (L.))
Buff-tip moth (Phalera bucephala (L.))
Common emerald moth (Hemithea aestivaria (Hübner))
Peach blossom moth (Thyatira batis (L.))
There were also some specimens of the invasive box tree moth (Cydalima perspectalis (Walker)), a pest of Buxus spp.
Box tree moth (Cydalima perspectalis (Walker))
General Nature Walk
After the moth traps were examined, Ros Taylor (DEFRA appointed Conservator) and Peter Haldane (Conservation & Engagement Officer) led the general nature walk to varied areas of the Common. Les Evans-Hill and Bill Budd also helped to identify what we found. Plenty of nets, pooters, jars (some with magnifying tops), guides and books were available to borrow.
Jars and pooters for collecting specimens
Books for identifying insects, pond life, plants, birds, etcetera
Identification charts from Field Studies Council
Our first stop was the hogweed patch. Earlier in the year, this area is dominated by cow parsley (Anthriscus sylvestris) but the taller hogwood (Heracleum sphondylium) takes over. Other plants in the patch include brambles, stinging nettles (Urtica dioica), bindweed (Calystegia), ribwort plantain (Plantago lanceolata), thistles, cleavers (Galium aparine) and horsetail (Equisetum arvense).
There are lots of insects and snails in the hogweed patch.
Beetle on hogweed
Rose chafer (Cetonia aurata (L.))
Banded snail (Cepaea sp.)
In the clearer areas near the path, other flowers such as meadow cranesbill can grow.
Meadow cranesbill (Geranium pratense)
From the hogweed patch, Ros led us into woodland. The woodland areas of the Common need to be managed by clearing paths, creating glades, removing excessive undergrowth and occasionally felling trees. This all helps to maintain a variety of habitats so that more species can flourish
Ros Taylor with group in woodland
On the edge of the woodland, one birch tree (Betula pubescens) had large numbers of shield bug nymphs on a few of its leaves:
Nymphs of parent bug (Elasmucha grisea (L.)) on birch leaf
Also near the edge of the woodland, there are patches of rosebay willowherb.
Rosebay willowherb (Chamaenerion angustifolium)
The next stop was Hookhamslade Pond, hidden away in another area of woodland. Angela Evans-Hill drove a buggy to meet us there with refreshments and with several pond nets that were quickly put to use for some enthusiastic pond dipping by several children.
Examining the catch at Hookhamslade Pond
The specimens included leaches, phantom midge larvae, bloodworms, a small water boatman, a dragonfly nymph and lots of pink waterfleas. We also found some tiny frogs in the grass beside the pond.
Small common frog (Rana temporaria L.), developed from one of this year’s tadpoles.
This pond has developed an unusual surface film this year, and Alan Wood took samples so that Quekett members could try to determine what has caused it.
Scum-covered surface of Hookhamslade Pond
There are lots of plants growing around the pond, including alder, and we saw leaf galls on the alder, probably caused by the mite Eriophyes laevis (Nalepa).
Leaf galls on alder (Alnus glutinosa)
Close-up of alder leaf galls (each gall is about 1 mm across)
There were toadstools growing in the leaf litter near the pond.
Toadstool (Amanita fulva) in leaf litter
After leaving the pond, we walked through woodland to the plain. This area is mostly grassland, part of which is left uncut to encourage skylarks and other ground-nesting birds. Near the edge of the woodland, trees are invading the grassland and we saw several red poplar leaf beetles (similar to ladybirds, but without spots) on the saplings.
Red poplar leaf beetle (Chrysomela populi L.)
We could hear and see grasshoppers (short antennae) and crickets (long antennae) in the uncut areas of grassland.
Grasshopper (short antennae)
Roesel’s bush-cricket (Metrioptera roeselii (Hagenbach)) (long antennae)
Les Evans-Hill with the iRecord Ladybirds app for identifying ladybirds
Harlequin ladybird (Harmonia axyridis (Pallas))
Larva of harlequin ladybird (Harmonia axyridis (Pallas))
Ros introduced us to the flora of the plain, where the dominant grass is Yorkshire fog (Holcus lanatus).
Ros Taylor with group on the plain
In the area that is not cut (in order to encourage ground-nesting birds and a variety of insects), there are several common plants and one rarity (bee orchid).
Bird’s-foot trefoil (Lotus corniculatus)
Lesser stitchwort (Stellaria graminea)
Tormentil (Potentilla erecta)
Yellow rattle is semi-parasitic on grasses but it is allowed to grow on the plain so that grass does not dominate and flowers can flourish.
Yellow rattle (Rhinanthus minor)
White clover (Trifolium repens)
Very hard to spot among other flowers of similar colour, Ros showed us a spot where a few bee orchids were in flower.
Bee orchid (Ophrys apifera)
We saw lots of lichens on live and fallen trees, and just before the end of a walk we saw some on a wooden seat.
Lichens on oak bark
Lichens on a wooden seat
We are grateful to the Conservators for allowing us to use the Information Centre for our microscopes and cameras, and to collect specimens from the Common.
Thanks to Quekett member Malcolm Storey for identifying the cricket, the ladybird and the toadstool from the photographs.
Members of the Quekett Microscopical Club will be in the Information Centre again for Wimbledon Common Open Day on Sunday 9th September 2018.
Report and photographs by Alan Wood, except where indicated