Spring 2012 newsletter - Butterfly Conservation

Butterflies
of
Northamptonshire
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e buery habitats of Northamptonshire
Details of ten important sites with public access to see the bueries of the county
Descriptions, life cycles, trends and distribution maps of the 36 species resident in the county
Historical summaries of rare migrants and extinct species
300 photographs in full colour
Features on the work of Buery Conservation and management for key species, Gardening
for Bueries, ‘BB’ and the Purple Emperor
UK Price £11.99
ISBN 978-0-9520291-3-7
Orange-tip
Anthocharis cardamines
Male (wingspan 46mm.)
e Orange-tip is a well distributed and common buery in our area
and its conspicuous markings and tendency to roam over a wide area
mean that it is well recorded, though the vagaries of the s pring weather
ensure that there are uctuations in the population of the adults and the
number of observations from year to year. It would have been much more
numerous in the past but the destruction of hedgerows, drainage of wet
meadows, and intensive agricultural practices have changed the scale of
abundance.
Local Distribution and Status
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e delicate male Orange-tip cannot be confused with any other species,
the orange tips to the forewings being visible from some distance when
the species is in ight. On closer inspection these can be seen to have a
black edge and a clear, black discal spot. e female can be confused with
other Whites unless observed closely; it possesses similar markings to
the male but lacks the orange markings. When at rest with wings closed
both sexes have a moled green appearance on the hindwings created
by an arrangement of yellow and black scales. Male Orange-tips are very
photogenic when on Bluebells or Bugle owers.
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50 60 70 80 90 00 10
e appearance of the Orange-Tip in spring marks the true arrival of the
buery season. Its principal habitats are lanes, hedgerows, river banks,
damp meadows, roadside verges and woodland rides where its great
mobility makes it a common species. May is the usual month to look
for it though in recent years the rst specimens have begun to appear
consistently in April. ere is a single generation and by June few are seen,
except in late springs when it can be on the wing even into July. Breeding
success is determined by the weather since the buery only ies in
bright sunshine. If conditions are warm, it can still be on the wing into the
evening. As soon as the sun disappears behind a cloud it closes its wings.
Cow Parsley and Garlic Mustard are common roosts and the cryptic
underside colouring creates an excellent camouage. As the sun returns,
it slowly opens its wings before resuming the steady, undulating ight
which takes this mobile lile buery over a wide area. Males will patrol
endlessly up and down a set area looking for females. Days of intermient
sun and cloud are ideal for photographing this prey insect.
e beautiful underside markings of the male
L i f e C y c l e
Butterfly
Conservation
A number of foodplants of the crucifer family are used for egg-laying. By
far the most successful is Garlic Mustard, but Hedge Mustard provides a
good substitute while in damper areas and woodland rides Lady’s Smock
is also utilised. All three of these are also readily accepted as nectar plants
though the species will feed from a wide variety of owers. Caterpillars
have also been found on Tower Mustard, Bastard Cabbage, Honesty,
Garlic Mustard and even Oilseed Rape. Eggs have been recorded
on Shepherd’s Purse, but without success. When rst laid, the egg is
translucent but turns a bright orange within a few days and is the most
conspicuous of any buery species as it is laid on the stalk of a plant just
below the ower head. Several eggs found on the same plant stalk will
be the product of dierent females. e caterpillars of the Orange-tip are
renowned for their cannibalism when young.
e caterpillar usually feeds on the seedpods of its chosen plant. When
it rst hatches, it is orange with black spines and a black head. Later it
becomes greener, until when fully grown it exhibits a ne example of
counter-shading, lighter above and dark green below. is prevents it from
casting a shadow which would betray its presence as it rests alongside
the stalks or seedpods, a position which makes it quite dicult to spot.
Even so, many are eaten by birds. e chrysalis is extremely dicult
to nd in the wild and the buery spends around ten months in this
stage, including the winter. e mustard oil which it has derived from the
A mating pair, male above, female below
foodplants of the caterpillar makes the adult buery unpalatable to birds
and the bright orange of the male advertises this, an example of warning
colouration.
Over-enthusiastic trimming of roadside verges destroys the species in its
early stages but cutbacks in Local Authority spending have arrested this
trend and the buery has actually extended its range in Britain in recent
years. A few more wild patches le here and there in parks and gardens
would assist it further. Long may we continue to see this harbinger of
spring.
F e m a l e
E g g
Caterpillar
Chrysalis
Butterfly
Douglas Goddard & Andy Wyldes
e egg is easy to nd on Lady’s Smock
Butterflies of Northamptonshire
e caterpillar feeds on the developing seed pods of its foodplant
Jan F e b Mar Apr M a y Jun Jul Aug Sep Oct Nov Dec
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Buerflies
Northamptonshire
Douglas Goddard & Andy Wyldes
‘BB’ and the Purple Emperor
Denys Watkins-Pitchford, who wrote under the pseudonym ‘BB’, was an eminent naturalist-writer who was born in
Northamptonshire and spent his life here. His fascination for the Purple Emperor (Apatura iris) began when he was young
-“I used to spend hours reading about it in my Frohawk’s British Bueries, looking longingly at the colour plate which
showed the insect in all its regal purple sheen, and I used to think that the outside of its wings was even more beautiful,
with its greenish whorls and marblings and the rich coloured eye on the forewing tips.” ‘BB’ began a persistent search for it,
when he found that it was ‘most frequent in Northamptonshire and Lincolnshire.’
Old sites for the buery were Barnwell Wold and the woods around
In his book Ramblings of a Sportsman-Naturalist, ‘BB’ describes the life
Polebrook, while in Geddington Chase in 1878, a man had captured over cycle of this beautiful insect in great detail and reveals what a marvellous
a dozen in a single day. ‘BB’ also mentions newspaper cuings referring observer and entomologist he was. On hatching the caterpillar eats the
to an Emperor being seen and captured at Yardley Chase. A well-known eggshell and then moves to the leaf tip where few predators explore and
Victorian entomologist, the Rev. William Bree, rector of Polebrook, once where the moisture drains o to protect it. He describes the minute beetle
caught a specimen in his hat down a riding in Ashton Wold. On a visit Anthocoris nemorum and its devouring of the tiny caterpillars. Much skill is
to his church, ‘BB’ surmised that he must have preached on many a hot needed to protect them from other enemies, such as spiders and earwigs,
summer aernoon, his mind no doubt wandering to the rides of the
and to tend them so that they survive the winter.
adjacent woods where the Purple Emperor was found. He tells us the
buery was still at Ashton in 1943, but only as a rarity.
In 1973, ‘BB’ tells us that he released 25 adult Purple Emperors into ‘the
Chase’. It is not clear exactly where he means, but this was most probably
‘BB’s early searches for the Purple Emperor found much of the habitat
the ride in Fermyn Wood known as ‘Emperor Ride’, a few minutes’ walk
unsuitable. In 1940 while wandering round Monk’s Wood, a former good from his home. e following year, he found eggs to conrm that they
site for it, he describes meeting an entomologist of the old school with his had indeed bred there. On July 28th 1978 he found 18 eggs and a female
Emperor net 15 high, and he was amused by his pretended ignorance, intent on laying. In 1980, he refers to them as, “the Purple Emperors of
while ‘his sly thirst for information suggested he was a professional
mine (they really were mine, of my own stocking, for as far as I know, iris
collector.’ Aer a brief view of his long sought aer prize in Salcey Forest, did not occur in this forest in recent years).”
‘BB’ nally ‘came face to antennae with iris’ properly for the rst time in
1946. He accompanied Stuart Humfries, an eminent eye-surgeon, to a
wood in Oxfordshire. Having seen a Purple Emperor sele high up on
an oak leaf, he and Humfries seeing a timber truck with wheels nearby
dragged it under the tree, so that ‘BB’ could reach with his net. He made
a sweep for it but it had vanished into thin air. e same day a worn male
circled twice round his head and seled on his knee.
It is clear from his writing that oak woodland was ‘BB’s favourite habitat,
and he extols the wide rides bathed in hot sunlight on a July aernoon,
the cool shadows banding the rides, the sound of the turtle doves
and bullnches, humming ies and the smell of the Meadowsweet.
Subsequent visits to Salcey Forest brought many happy sightings of the
Purple Emperor before spraying to eliminate Oak Tortrix moths led to
its extinction in the 1960s. In 1948, he saw a female laying an egg and
plunged into a ditch to pull down a sprig of Sallow to inspect it. Salcey
also inspired his book Brendon Chase and here in a shady ride one day, he
encountered John Phillips, a Keering surgeon who taught him how to
nd the buery’s eggs successfully.
Eggs can be found on the lower branches of large Sallows but climbing
high into the upper branches may yield even more. One eminent
entomologist, a very big and heavy man, fell and injured himself so badly
that he died later. ‘BB’ regarded the death of a well-known collector, killed
aer falling in a ditch while searching for eggs, as a ing end, and was
prepared to take the risk on many occasions. Once able to gather eggs, he
admied that the ‘iris bug’ had bien even deeper and he vowed to tend
the caterpillars through the winter. It became his mission to reintroduce
the Purple Emperor to its ancient stronghold.
BB watches the release of his bueries into “Emperor Ride” in the mid 1980’s
photographed by Jack Steward
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of
In the 1982 season, he only found two eggs as the vision in his right eye
had become impaired to the extent that locating them was becoming
too dicult. By then, however, his labours had begun to bear fruit.
Ian Flinders’ survey of the bueries of Northamptonshire 1976-81
had deemed the Purple Emperor extinct but subsequent to this, local
enthusiasts had begun to nd it again in the woods around Brigstock.
It could be seen only a few hundred yards from the Round House in
Sudborough. During the 1990s it had begun to appear regularly and
extended its range here so that it is now found throughout most of the
old Rockingham Forest. In the current millennium Purple Emperors
have been seen regularly in the Silverstone area, particularly Bucknell
and Hazelborough Woods and, on one occasion, Whistley Wood. e
species was recorded again in Yardley Chase from 2009 and a discovery of
a caterpillar by a Northants Wildlife Trust worker conrmed its breeding
there in 2011. is year also saw its return to Salcey Forest aer half a
century with two separate sightings.
Above: A male and female Emperor raised by ‘BB’ are released into ‘Emperor Ride’ in the mid 1980s. Photograph by Jack Steward
Right: e Round House at Sudborough, ‘BB’s home for a number of years, right on Fermyn’s doorstep
Below: ‘Emperor Ride’ in Fermyn as it is today
As a result of climate change the Purple Emperor is extending its range
nationally. It has become widespread in Oxfordshire, another old haunt,
and has been recorded in Warwickshire, Suolk and Cambridgeshire in
recent years. Sallow regenerates quickly on the clay soils of our county and
Fermyn Wood has the perfect conditions for it, the habitat developing
particularly aer ‘BB’s death in 1990. What role the writer played in its
current expansion is dicult to establish. It may be that the buery was
there all along and his intervention helped the population to reach the
level where it began to be seen more readily. It is nonetheless a source
of great pleasure to feel that current buery enthusiasts are treading in
the same woodland rides into which he ventured and to reect that his
cherished dream of seeing ‘His Imperial Majesty’ ying there again is now
an ongoing success, a ing monument to this great naturalist.
By Douglas Goddard & Andy Wyldes
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