Skip to content

Invertebrates

There has been a count of moths on the Bishop’s Meadow. At least 27 species of moths are fluttering in the night skies according to Martin Angel of the Bourne Conservation Group. This is really lovely news for the trustees who were excited last year by the news that a rare visitor was observed in amongst the reeds, a dragonfly of distinctive scarcity called the scarce chaser Libellula fulva.SCARCE CHASER

Amongst the moths is another local rarity seldom recorded in Surrey, the Kent Black Arches Meganola albula. There are 2500 species of moth and butterfly in the UK, and we have at least 1% of them.

Moths aren’t just plain butterflies. Lepidopterists distinguish the differences between the two in a very narrow way, and even when the distinctions are made, nature shifts the rules. Most butterflies have club tipped antennae, some moths do too. Most moths form a cocoon made from silk, whereas butterflies create a pupae. Hawk moths don’t make a cocoon. Moths have larger heat retaining scales on their dusty wings, and have fatter, hairier bodies to protect them in the cooler night air, and to deflect the radar of marauding bats. Butterflies are svelter, being day time dancers, and are able to absorb more sunshine.

But all of this is very empirical, moths being distinct from butterflies. It’s far more interesting to understand what they’re for. Why moth. Why butterfly. What’s their role?

The thing to get is pre-civilised European wilderness. After the ice retreated, nature responded with huge forests, endless prairies, teeming herds of grazing animals, and endless clouds of birds, unbroken swathes of plant communities jostling and competing for light. Each plant stretching out for sunlight sought a competitive advantage, and co-operated with insects and animals to do so. Take the Mullein moth, Shargacucullia verbasci, for example. Mullein, or Verbascum, shoots up a towering spike of thick hairy leaves, which get ravaged by stripey caterpillars. The stately plant is left in rags, its energy giving chloroplasts chewed into threads by voracious grubs. The waste product of this is huge amounts of tiny droppings some of which get trapped in the remaining hairs, and the rest plummets to the ground, fertilising the ground around the base of the plant. The flowering follows that extra bit of nutrition, and a spire of yellow flowers would be carried high above competing grasses and plants to be pollinated by insects feeding amongst the multitude of flowers and leaves.

Mullein and Moth co-operating, and as we know from studies made in both forests and meadow, an individual species of insect will have been co-operating with individual plants for thousands or indeed millions of years. Our meadow moths are no different, and feed on various wildflowers and plants which we call weeds, but moths call dinner. Many of our moths use plants to feed on or to adapt the plant in some way as part of its life cycle.

The problem is of course that the wilderness has been conquered by human activity, and these swathes of co-operation smashed and broken down into tiny remnants of this magnificent past. Our meadows is a remnant grassland of a much vanquished culture, it’s a kind of shadow or hint of type of landscape that may have existed thousands of years ago, but being a river valley, these meadows would once have been home to alder glades, cleared in the Roman occupation for their rot resistant timber, drained and converted to grazing by late Celtic and Saxon settlers. So the grasses and wildflowers that ensued would have sought amity from the moths and butterflies living in the untamed prehistoric landscapes around the tribal farmlands, and partnerships would have developed. In these organic times, human and animal manure were the key fertilisers, and petro chemicals were unknown. Insect life would have been abundant.

Now, we have a miniscule selection of wildflowers, whose dominance has been overthrown by vigorous grasses. The feed plants of moths and butterflies have diminished as the grasses have prospered, and the cycle of cattle grazing the late summer pasture is for now gone. The cattle would have replicated to some extent the grazing of herd animals on the grassland, and humans providing the role of apex predator. The trampling action of hooves would have allowed the passage of flower seeds, and the seeds would have burst into bloom in the early summer, feeding countless hoverflies, bees, moths and butterflies. Without the cattle, without the flower diversity, without the subtle human interventions, and without the constant change of vegetation use, the numbers of butterflies and moths has sharply decreased, because simply, there is not enough forage for them.

But we do have our 27 species of moth and at least 16 species of butterfly (at the least) flitting in our fields. We have our rare fellow, and our marbled whites. We are cutting the grass for hay once a year to encourage the wildflowers, and we will do our best to open bits of ground to let the wildflower seeds through. We will improve the meadow edges and increase the variety of hedge plants and flowers to provide anchor holds for passing foragers and browsers.

BCGLogoWe owe a huge gratitude to Martin and the Bourne Conservation Group for this survey. The full list of moths identified by Martin is attached as is a set of photos of some of the species identified. Bishops Meadow Moth Species – photos

The 16 species of butterfly recorded on the meadows include:

Common name

Scientific name

Small tortoise shell Aglais urticae
Orange tip Anthocharis cardamines
Ringlet Aphantopus Hyperantus
A spider Araneus quadratus
Beautiful demoiselle Calopteryx virgo
Holly blue Celastrina argiolus
Common blue Cupido minimus
Small blue Cupido minimus
Brimstone Gonepteryx rhamni
Peacock Inachis io
Meadow Brown Maniola jurtina
Marbled White Melanargia galathea
Water boatman Notonecta glauca
Speckled wood Pararge aegeria
Large white Pieris brassicae
Green veined white Pieris napi
Small white Pieris rapae
Comma Polygonia c-album
Gatekeeper Pyronia tithonus britanniae
Common red soldier beetle Rhagonycha fulva
Small Skipper Thymelicus sylvestris
Red admiral Vanessa atalanta
Advertisements
No comments yet

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: