Click Photo to enlarge The moth skills improvement group met at Elm Farm, Burnett on 29 October and at
Brown’s Folly on 9 November to look at leaf miners. These are very small moths
whose caterpillars feed within the thickness of a leaf but evidence
of their feeding is left behind . The mines which are created can be seen either as a blotch or
a linear feature. In many cases the moths are host specific and can be
identified by using a key based on a combination of the plant species and a
description of the mine. Probably the best (i.e less commonly recorded)
moth was found on Bramble at Elm Farm. The picture shows the mine of the very
common Stigmella aurella on the left and the much scarcer Stigmella
splendididissimella on the right. The distinguishing feature is the line of
frass (caterpillar poo) left behind as the larva progresses through the leaf.
S. aurella leaves a thick line whereas S. splendididissimella leaves
a thin line only occupying 1/3rd of the width of the mine. Thanks to Mike Bailey
I am pleased to say that we now have over a thousand photos on
the Bath nats Flickr site all taken by Bath nats members all of which are
within our recording or on field trips, thank you all very much a few more contributors
always welcome. Link to Bath Nats.flickr site
Piptoporus betulinus, commonly known as the birch polypore. Most often seen on dead Birch, however it often lies dormant in live trees and when the tree becomes 'stressed' through whatever means such as old age, disease or drought say the it causes 'brown rot' and the eventual death of the tree.
The fruiting bodies as shown in the photo were once used as razor strops. They are also the food plant for a number of beetle and insect larvae.
Click Photo to enlarge
Spindle (Euonymus europaeus) this small tree or shrub is found in our older native hedgerows most commonly growing on a lime soil
At this time of year (November) it has unusual pink berries which were once ground in to a powder to eradicate head lice.
The wood was used to make such things as wooden skewers, pegs and knitting needles.
The Spindle can often be seen in the spring covered completely in silk webs and totally defoliated by the Spindle Ermine moth (Yponomeuta cagnagellus)
The sighting of these bees has been reported to BWARS who
are mapping the spread of this species.I understand a Bath Nats visit to
Victoria Park saw another aggregation of these bees at the end of September.
There were many hundreds over the bare ground on at least two allotments off
This is one of the species found in the UK with the common name of 'false widow'. It's also called the cupboard spider. They seem to be quite common in this area and I have found a number of these in the house. Their favourite prey being Woodlice. Apparently their bite is akin to that of a wasp so treat them with respect if you find one.
“Birth of Biodiversity SIG -
Prospecting for Woodland Lichens, Bryophytes and Fungi at Elm Farm” 30th October 2012
Alan Feest and Alan
Rayner have decided to start a new ‘Biodiversity Skills Improvement Group’,
with the intention of helping Bath Nats members develop ecological
understanding and survey skills in an enjoyable, focused and participatory way,
which includes a lot ‘more than making a list’. To join the group, just send a
note of your contact details to one or both Alans, and they will let you know when
and if they have something planned and what it is.
As a way of getting
started, the two Alans met together with Marion Rayner, Philippa Paget and Ian
Stapp on Tuesday 30th October 2012, to undertake a ‘structured
survey’ of lichens, mosses, liverworts and macrofungi present in an area of
20-year-old deciduous woodland at Elm Farm. We recorded everything we could
find and identify in a set of 20 8 metre diameter localities, approximately 20
metres apart. In this way we collected a ‘baseline’ list that will enable us to
detect and measure any change that has taken place when we or somebody else
repeats the exercise in months or years’ time when the trees will have grown
and/or (in the case of ash, now threatened by die-back) died. We also had great
fun and discovered, learned and – with the aid of Ian’s photography - recorded much
that we wouldn’t have done without working together intensely, combining our
different skills and interests. Philippa’s enthusiasm for digging in the dirt
unearthed some tiny fungal fruit bodies, including Delicatula integrella, Clitopilus
hobsonii, Microtyphula filiformis,
Typhula erythropus and Clavulina rugosa, growing on twigs and
soil, and Marasmius recubans and Mycena capillaris growing respectively
on decaying beech leaf petioles/veins and laminae (see Ian’s photograph below).
Rayner’s focus on tree bark and branches revealed a surprisingly large variety
of lichens, whose identification was not always made easier by parties of slugs
and snails, which munched their way through some species (e.g. Arthonia radiata) more than others (e.g.
We were puzzled for a
while by the sudden change in lichen cover evident on many trees about 1 metre
above the ground. Then we came across a tree with its original protective
shelter still partly in place. In the moisture underneath this, Marion was
excited to encounter what later proved to be the liverwort Riccardia chamedryfolia, along with the ‘stringy moss’, Leptodictyum riparium, an inhabitant of
water films sometimes grown in fish tanks, which she added to our smallish but
significant list of bryophytes growing on the ground, around the base of trees
and – in the case of Orthotrichum affine higher
up trees in the wrinkled bark where branches emerged from the main trunk.
Assessment of the data showed that the
biodiversity of bryophytes, lichens and macrofungi at Elm Farm was higher than
for Primrose Hill which we had surveyed previously. We now have baseline data
for both sites that we can compare in the future to detect biodiversity trends.
Interestingly, despite the higher biodiversity at Elm
Farm both sites showed the effects of nitrogen, with Bryophyte Nitrogen
Indices of 5.67 at Elm Farm and 6.2 at Primrose Hill. Anything above 4.0