Dragonflies and damselflies

On Saturday we visited some ponds where Fred had not collected samples before. There were large numbers of insects visiting the ponds, including these damselflies.

Male Emerald Damselfly (Lestes sponsa)


Female Emerald Damselfly


Pair of Emerald Damselflies

Pair of Darters (probably Black Darters - Sympetrum danae)

Watch a video of two pairs of Darters laying eggs.

I also found this empty larva case (exuvia) of a Common Hawker (Aeshna juncea) - one of the larger dragonflies.

One of the dragonflies even settled on Fred's head!

Many thanks to Jeanne Robinson for help with identifications.

Further information:

British Dragonfly Society - includes photos of British species
and a useful pdf document on Dragonflies in your garden

Ophrydium

On Thursday I went up Ben Venue. Close to the summit (which can be seen in this picture) there is a small pond which sometimes dries out.

Below is a photo of the pond taken early in the year, looking the other way, towards the trig point which is at the second top of the hill.

In this small pond I noticed some greenish masses and I thought this would be something to interest Fred so I tried to collect some. This proved difficult, as it kept slipping out of the collecting tube, so I used a bag instead.

Under the microscope, this turned out to be tiny protozoa, each containing green algae. We identified them as Ophrydium, though this usually grows in a much more defined greenish spherical jelly-like lumps. Maybe this was an old colony.

The creatures have tiny beating hairs at the front...

...and a long point at the rear.

Our videos:

See also:

Green jelly balls of Ophrydium versatile

Droplet: amateur microscopy of the Protozoa

Protist Information Server

Size dependence of composition, photosynthesis and growth in the colony forming freshwater ciliate, Ophrydium versatile. Freshwater Biol. 31: 121-130

Some notes on an uncommon colonial peritrichous protozoon, Ophrydium versatile (O.F.M.). E.D. Hollowday. Microscopy 32, July-December 1975

Hawthorn Shield Bug

Yesterday I met a small creature resembling an alien in our garden.

It was a Hawthorn Shield Bug (Acanthosoma haemorrhoidale).

It was very co-operative about having its photo taken, and afterwards I put it on a cotoneaster bush, as I think it must have dropped out of it while I was pruning.

When I went out again an hour or two later, there was a second Shield Bug sitting close by, which I hadn't noticed before. It must have been attracted by the presence of the first one.

These bugs go through five larval stages called instars.

This morning, when I went to the garden waste bin to add some more prunings, I discovered what I now recognised as an immature Shield Bug inside the bin. (I also made a mental note always to shake any prunings before putting them in the bin in future, so that these small creatures don't get sent away with the waste)

Later I found 2 more smaller ones. This is the biggest and the smallest at 11:50am...

...and the middle-sized one at 1:50pm, with the small one hiding under a leaf on the left.

1:50pm. The biggest and smallest. The smallest had already changed colour, so it must have gone through a moult.

17:30. I went to have another look, and the biggest one had now changed completely. I think this is the 5th instar stage.

17:45pm. Meanwhile, the smallest seemed to be moulting again.

8th October 2009

Today I found this shieldbug crawling on the lid of one of our compost bins. It is a Birch Shield Bug (Elasmostethus interstinctus) and it measured 8.5mm excluding the antennae - slightly smaller than the Hawthorn Shield Bug. Note that the projections on the pronotum (the widest bit just behind the head) are smaller and not tinged red.

16th October 2009

It has been a while since I saw any Hawthorn Shield Bugs, but I discovered this 5th instar today on the cotoneaster bushes.

More information can be found on the British Bugs website.