Wednesday, 11 July 2012

Denso Marston Nature Reserve - Sunday 8th July

This was our second visit to this hidden gem of a nature reserve in our two-year history. We had a pretty good turnout, considering Andy Murray was playing in the Men's Final at Wimbledon at the same time! Thanks to everyone who joined us – we had a great time bug hunting and pond dipping, and the weather was great too!

After a welcome from our host, reserve warden Steve Warrillow, we set out on a ladybird survey. We found lots of ladybirds, like the Two-spot and Seven-spot; but the most abundant was the recent invasive species the Harlequin ladybird.

 Harlequin Ladybirds at Denso Marston Nature Reserve
(photos Angie Wilson)

We even found a Harlequin larva, which will eventually turn into a fully-grown ladybird. This larva this is the stage in the ladybird lifecycle between egg and adult (a bit like a caterpillar is the stage between egg and butterfly).

 Harlequin Ladybird larva (photo Jane Cameron)

The Harlequin is a native of eastern Asia and was introduced into North America in 1988 to control aphids It has since become the most widespread species there. The Harlequin was also introduced on to mainland Europe and arrived in the UK in 2004 and is spreading rapidly. Harlequins have the potential to wipe out some of our 46 resident species of ladybird. If you see any Harlequin ladybirds while you are out and about why not report them here and help monitor the spread of this species, which will help us to understand their effect on our native ladybirds.

We also caught a variety of other bugs in our nets. We found three different types of butterfly: the dark Ringlet, the brown and yellow Speckled Wood, and the brown and orange Meadow Brown; and three types of damselfly: a Blue-tailed, an Azure, and a fantastic Banded Demoiselle.

 Blue-tailed Damselfly

There were lots of other small bugs too, like the Straw Dot Moth, Capsid Grass Bugs, bright green Aphid, and the red Soldier Beetle.

 Peacock Butterfly caterpillars

While we were searching for ladybirds we came across these magnificent caterpillars of the Peacock butterfly. Each one of these caterpillars will soon transform into a chrysalis and turn into a butterfly!

 Peacock Butterfly

During our walk through the reserve we found some patches of carpet, which have been left by Steve to provide shelter for minibeasts. Under these we found lots of young amphibians, like this fantastic Common Toad and Smooth (Common) Newt!

Common Toad
Smooth Newt

Under many of the leaves of the plants on the riverbank were lots of Banded Snails, including the White-lipped Banded Snail. They had all kinds of stripy patterns on their beautiful shells.

Banded Snails

After lots of bug hunting we swapped our bug nets for pond nets. After a good sweep of the pond we captured some very interesting creatures and put them into our jars for closer inspection. These included: Lesser and Greater Water Boatman, Water Hoglouse, Water Flea, Water Snail, and a Leech.

Pond Dippers!

We found some large tadpoles, probably young Toads, and lots of young Smooth Newts with feather-like external gills. We also found two scary-looking dragonfly larvae!

 Brown Hawker Dragonfly larva

This larva was huge and is probably very nearly ready for its transformation into a dragonfly - we think this one will turn into a Brown Hawker Dragonfly (we also saw one of the adults fly over the pond).

These larvae (or nymphs) are formed after a pair of dragonflies mate, the female will then lay her eggs in a pond or lake, either on a plant or just straight into the water. The dragonfly nymph hatches from the egg. They look very strange, almost alien, and don’t have any wings. After about four years in the pond the nymph will crawl up a reed stem and an adult dragonfly will break out from the outer casing. The dragonfly will wait for an hour or so for its wings to dry and will eventually take to the skies. This dragonfly will eventually mate with another and the process begins all over again!

Did you know adult dragonflies only live up to two months? But don’t forget it has lived for up to 4 years as a nymph before this! Take a look at The British Dragonfly Society website to learn more fun facts about dragonflies!

Thanks again to everyone who came to this event, and special thanks to Steve from Denso Marston Nature Reserve for showing us the wildlife on this great reserve.