We 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. 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
White (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