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After two visits to the Rainham Marshes this year, I wanted to explore other local sites in Essex. The Chafford Gorges (owned by the Essex Wildlife Trust) are local to me and seemed interesting because of their flora and history. They are located in the the Chafford Hundred area which is mostly a modern housing development, and is adjacent to one of our huge regional shopping centres, Lakeside. The three gorges are all that remain of a much larger wild area that I remember from my childhood.

A shot of one of the nearby chalk pits (mostly filled with Birch)

When I visited with Tristan I went to Grays Gorge and Lion Gorge. At Grays Gorge I saw my first wild British orchid, the common spotted orchid, Dactylorhiza fuchsii.

Common Spotted-orchid, Dactylorhiza fuchsii

We were fortunate to meet the site warden whilst we explored, and hopefully I will be able to acquire some old records for insects in the area.

Somewhat anecdotally, I recall seeing glow worms, Lampyris noctiluca, on the nearby cliffs when I was younger but do not recall seeing them after a road was built nearby, which would have coincided with increased light in the area from both new houses and street lights. Perhaps this can be seen from the local records…

Some photos from the gorge area:

A lucky shot

The rather attractive Cercopis vulnerata

A few weekends ago I visited Wicken Fen, the UK’s oldest nature reserve. Since it was first bought in 1899 by the National Trust, the area of the reserve has increased from 0.008km² (2 acres) to 7.7km², and the trust plans to buy more of the surrounding land to enlarge it further.

Wicken Fen

The habitat of the reserve is a remnant of the formerly vast Cambridgeshire fenlands, land which is now used almost entirely (99.9%) for farming. The fen has long been a place of interest for entomologists, and continues to be so: as well as being species rich, the British Dragonfly Society will be opening a dragonfly center at the fen later in the year.

Even though I visited early in the year, the weather was nice and sunny, and I saw many insect species for the first time. On the start of our walk my girlfriend found a prowling water scorpion, Nepa cinerea, which was an exciting first Heteropteran bug of the year! This was also my first proper opportunity to use my new macro lens, and although I am still learning many basics, I was happy with most of the photos I took.

Water scoprion, Nepa cinerea

Some other firsts for me was seeing a slender groundhopper, Tetrix subulata, and a 24-spot ladybird, Subcoccinella 24-punctata. Whilst my girlfriend is (fortunately) fond of insects, she was particularly excited to see a common lizard, Zootoca vivipara, basking in the sun.

Common lizard, Zootoca vivipara

On the way back I saw many mining bees, Andrena clarkella, digging their burrows around an oak tree.

Mining bee, Adrena clarkella

I am hoping to visit Wicken Fen again soon, perhaps during my next holiday.

The beetle family Scarabaeidae contains some well known British insects like the chafers and scarabs, of which the most notable species is probably Melolontha melolontha (cock chafer/may-bug).  Of the 20,000+ species in the family, none were known to be primarily carnivorous, with most members eating plant matter or dung.

Melolontha melolontha, a British member of the Scarabaeidae family

In the Scarabaeidae subfamily Scarabaeinae the principal food stuff is dung, although some species eat carrion, rotting fruit or fungus. In a recently published paper one Peruvian species in the Scarabaeinae subfamily, Deltochilum valgum, has been found to be a predator of millipedes (Larsen et al, 2009).

In comparison to other dung beetles, D. valgum has a modified head, hind legs (the tibiae) and abdomen (pygidium), which makes it suited for attacking and feeding on millipedes. The beetle uses part of its head, the clypeus, as a lever to prise apart segments of a millipede’s body, often resulting in decapitation.

To test food preference the experimenters used a variety of bait traps containing dung, carrion, fungus, fruit and millipedes. They found that D. valgum was only attracted to millipedes and that it preferred millipedes which were injured but still alive.

Thanks to Linda for showing me a BBC News article on this. Irritatingly the BBC had inadequately referenced the study, so it took me a little while to find the actual article.

References:

Larsen, T.H., Lopera, A., Forsyth, A. and Génier, F. (2009) From coprophagy to predation: a dung beetle that kills millipedes. Biology Letters, 20th January [Online] Available at:

http://journals.royalsociety.org/content/g17124g4q8733365/

[Accessed 21st January 2009]