Week 31: Butterfly Finale & Next Gen Bugs

I had my first blog-related nightmare this week. I dreamt that I arrived at Dellfield only to discover that over night there had been a kind of landslide/sink hole catastrophe. The whole meadow had sunk by about 4 foot. The Oak and Scots Pine had been completely uprooted and lay destroyed, on their sides, as if gunned down. Part of Hay Wood had slipped down the hillside and the whole area was unrecognisable. I couldn’t quite believe what I was seeing but, with dawning realisation, I actually began to cry. I guess over the past 8 months, Dellfield, the Oak and the Pine have become like old friends. Let’s hope I’ve not been blessed with the gift of prophecy!

Monday morning, I decided I’d concentrate my efforts on Bovingdon Reach meadow at Westbrook Hay. A group of about 15 Swallows were flying less than a foot above the ground, chattering to one another and searching out insects. My car thermometer read 13 degrees Celsius so it felt a little chilly although the sun did occasionally find its way through the banks of grey cloud (see photograph above for grey cloud proof!).

My first find was an immature (mid instar) Bronze Shieldbug (Troilus luridus) on Hawthorn berries. It’s a predatory bug which feeds on other insects although the nymphs (immature stages) also feed on plants. It occurs widely across the the UK but I’m not sure how common it is in Hertfordshire. There’s one generation per year. If you're interested, you can find pictures of the adult here.

Next up was a Hairy (or Sloe) Shieldbug (Dolycoris baccarum), so called because, well, it’s covered in hairs. At around 11-12 mm in length, it's twice the size of the tiny little Woundwort Shieldbug of Week 19. “It overwinters as an adult, emerging in the spring. Larvae, which are also hairy, may be found on numerous plants, particularly those in the Rosaceae. The new generation is complete from August onwards.

"It's common and widepsread in many habitats throughout Britain, particularly hedgerows and woodland edges, becoming scarcer and mainly coastal in the north”. It was a new species to me so I was chuffed to encounter it. I'm not sure if this is a fresh adult from this year or one from a previous generation. It's also just beginning to lose its lovely purple summer colouring and adopting its duller, brown winter hues.

Hairy Shieldbug (Dolycoris baccarum)

Finally, as I made my way towards Hay Wood, I spotted a Small Heath butterfly (Coenonympha pamphilus). These seem to be very scarce locally and I think this was only my second sighting this year (the first, I think, being a fleeting view at Roughdown Common, late Spring/early Summer). Anyway, I was pleased to manage a photograph this time before I lost it again. The larval food plants are grasses, specifically Bents (various) (Agrostis spp.), Fescues (various) (Festuca spp.) and Meadow-grasses (various) (Poa spp.).

Tuesday was a little warmer and much sunnier. Further Roughdown was covered in the white frosting of Eyebright and the purple splashes of Marjoram. Common Blue butterflies aplenty. I keep hoping I’ll come across a Chalkhill Blue or some other chalk plant loving species. Roughdown Common always feels like a habitat full of promise. And….it is...

A couple of immature (late instar) Dock Bugs (Coreus marginatus) were together on a bramble leaf (photographed left), up on the south-west side of Lower Roughdown. And, after wandering the bank, bordering the A41, I eventually spotted what I suspect will be this year’s butterfly finale, a species I was extremely pleased to find and one which just goes to prove the potential of this site. A Brown Argus (Aricia agestis). Having corresponded with a couple of experienced, local butterfly recorders, it seems that the Brown Argus is another local scarcity. Two were observed in 2012 at Roughdown Common, none last year.

Colonies of Brown Argus butterflies are generally found on chalk or limestone downland, where the primary larval food plant, Common Rock-rose thrives. Adults feed on Marjoram (Origanum vulgare) as well as Ragwort (Senecio jacobaea), Thyme (Thymus polytrichus) and White Clover (Trifolium repens). Roughdown Common certainly has the habitat to support this species but it’s obviously still only 1 or 2 specimens, if we're lucky.

Butterfly Finale - Brown Argus (Aricia agestis)

Project 2014 was never meant to be a scientific monitoring or recording of species around the Box Moor Trust sites. It was much more about enjoying the land and just seeing what turned up. However, I think that the Brown Argus was the 26th species of butterfly I’ve seen on Trust land this year, which speaks volumes to the quality of the developing habitat. According to Herts and Middlesex butterfly records for 2013, there are a total of 35 possible species present across the counties. Those I've not seen at the Box Moor Trust sites this year (so far):

1. Grizzled Skipper
2. Clouded Yellow
3. Purple Hairstreak
4. White-letter Hairstreak
5. Small Blue
6. Chalkhill Blue
7. White Admiral
8. Purple Emporer
9. Dark Green Fritillary

Species I have seen at the Box Moor Trust sites this year:
(if I saw them at one site only, I’ve indicated that [BW = Bovingdon Brickworks; RD = Roughdown Common])

1. Brimstone 2. Comma 3. Small Tortoiseshell 4. Peacock 5. Holly Blue (RD only) 6. Green Hairstreak (RD only)     7. Red Admiral 8. Orange Tip 9. Small Copper

10. Common Blue 11. Dingy Skipper (BW only)     12. Large Skipper 13. Small Skipper 14. Essex Skipper 15. Meadow Brown 16. Ringlet 17. Marbled White 18. Speckled Wood

19. Gatekeeper 20. Green-veined White 21. Small White 22. Large White 23. Painted Lady (BW only) 24. Silver-washed Fritillary (BW only) 25. Small Heath 26. Brown Argus (*)

Still time for a Purple Hairstreak at Roughdown so I'm keeping my eyes peeled!

*NOTE 2 Sept 2014: Following the Brown Argus at Roughdown Common, I then found a colony of at least 13 individuals at Bovingdon Brickworks.

Week 3: Life Around The Oak

A grey, overcast morning. I decided to take a closer look at the life immediately on and around the Oak. Westbrook Hay is a popular place for dog walking, walking and running. One chap was successfully combing all 3, I think. Obviously, the Oak does not exist in splendid isolation and is in fact home to and supported by all manner of organisms, seen and unseen. A couple of the more conspicuous connections are the two plants sprouting near its base. The 3 species no doubt share a complex root system, involving a mutualistic relationship with mycorrhizal fungi. Although commonplace, I still find this plant-fungus relationship amazing:

Above ground, the plant does all the hard work in terms of capturing the sun’s energy via photosynthesis, converting it into useful carbohydrates. Below ground, the roots of the plant are infected with a fungus which has the superb ability to seek out water and to absorb high levels of nutrients from the soil. The fungi feeds on the plant’s carbohydrates. The plant feeds on the nutrients and water secured by the fungi. Both gain and thrive as a result. Beautiful!

A is an Elder, which is largely dead and home to interesting fungus and lichen, two of which I photographed, below.

Common Orange Lichen (Xanthoria parietina)

Jelly Ear (Auricularia aricula-judae)

Knowing very little nothing about these species, I discovered that the Common Orange lichen is highly tolerant of nitrogen rich environments, especially where ammonia is present, and thus, it is common on trees and buildings near farm land: the slope above Dellfield is home to grazing sheep. As for the Jelly Ear fungus, it is predominantly, although not exclusively, found on Elder. A useful fact to know if you want to identify the (dead) wood it's inhabiting. Unfortunately, the specimens I found were past their best, dried up and crusty. It does look rather different when it's fresh. Wikipedia has all sorts of wonderful tidbits about the origin of its name and how the fungus was used in folk medicine.

The second plant, B, is a Hawthorn, with its long spines and bright red berries. Around its roots and those of the Oak, are the remnants of last year's fallen acorns (with a bit of sheep's wool thrown in for good measure). To my surprise and delight, an additional life supported by the tree came in the guise of a small mammal, darting from the base of the Hawthorn, into its home under the main Oak trunk. I suspect it was a little Wood Mouse, nibbling on the acorns. Unfortunately, s/he was far too quick for my eyes or camera!

Overhead, a Red Kite was calling and, in nearby trees, a couple of Mistle Thrushes were rattling away.

Finally, a shot of the "chosen" branch of the oak, backlit by the densely cloudy sky. I'm not sure yet whether the idea to photograph a single branch weekly was a good one or not. I'll see how it develops.