Members
recently enjoyed a presentation entitled Butterflies of The New Forest by Jacky
Adams and Nigel Owen, both active members of Butterfly Conservation. The life
cycle of butterflies comprises four stages: egg, caterpillar or larva,
chrysalis or pupa and adult butterfly. The caterpillar stage is when the
serious eating happens and they change their skins as they grow larger; the
nectaring by the adult serves only to keep it alive during its’ flight period. How
long is spent in each stage varies from species to species - for example the
Green Hairstreak spends 9 - 10 months as a pupa; the Pearl-bordered Fritillary
spends 10 months as a caterpillar. The phase in which each species over winters
varies: many do so as caterpillars, finding a secluded and safe spot. The
Speckled Wood can over winter either as a caterpillar or as a chrysalis. Five
of our resident species over winter as adult butterflies, Red Admiral, Comma,
Peacock, and Small Tortoiseshell (our favourite garden butterflies) and the Brimstone,
which could be regarded as the harbinger of spring. These adult butterflies,
when they emerge in spring do of course create the first generation of the new
year. The Small Tortoiseshell has been suffering a serious decline in numbers
for some years and a staggering 32% drop in sightings this year. The
caterpillar of the Comma once ate hops exclusively but with this in
increasingly short supply had the good sense to start eating nettles like the
others in this group (save for the Brimstone) and reversed a serious decline
some year ago.
In
Britain there are about 59 resident and regular migrant species many occurring
in the New Forest. Getting to see them will depend upon the correct habitat,
the time of emergence and, importantly, good weather, preferably warm sunshine.
Sometimes the rarer the butterfly is the shorter the flight period, examples
being Pearl-bordered Fritillary and Duke of Burgundy (Fritillary). In contrast,
the speckled wood is available throughout the summer with successive broods and
it will also fly in conditions that other butterflies dislike. In addition to
the “garden species” mentioned above the whites may also be found in ones’ garden.
These are the not so popular Large and Small Whites (the scientific name of the
Large White is Pieris brassicae!) the
Green-veined White and the Orange Tip. The caterpillars of the latter two do
not eat cabbages but cruciferous plants.
The
New Forest has its’ share of the rarer butterflies. There are a few colonies of
Pearl-bordered Fritillary, formerly a common species in coppiced woodland. The
beautiful White Admiral with its’ floating flight can be found in some areas of
shady woodland. Clouded Yellows arrive here in varying numbers and can sometimes
be seen particularly on the coast or downland. There are reports of them
overwintering infrequently. In contrast the migrant Painted Lady cannot survive
winter temperatures whatever stage has been reached in the breeding cycle; this
butterfly very occasionally arrives here in tremendous numbers. The Glanville Fritillary’s
stronghold is on the Isle of Wight though attempts to establish itself here on
the coastal mainland have been short-lived only.
The
speakers concluded by describing how we can all help encourage butterflies in
the garden by growing nectar producing flowers and allowing some nettles and
long grass to grow. Also to participate in the annual Big Butterfly Count and
consider joining the New Forest Transect Group to carry out counts on a regular
basis. AB