Members
of this interesting group of medium to large moths are notable for their
exotic colourings and behaviour, being related to over a 1000 species
worldwide, most of which are found in the tropics. Some Hawkmoths (about
8) are resident in the UK, but a few others migrate here from Southern
Europe and Africa.
Easily
the most abundant resident in Cumbria is the Poplar
Hawkmoth (photo left). It is easily recognised
by its unusual shape, not least because at rest its hindwings
project well beyond the leading edge of the forewings. It is
attracted to light but may occasionally be disturbed from a
resting place during the day, especially around its foodplants
of Poplars and Sallows. Unlike most other hawkmoths it has a
short proboscis as adults don't feed. It is on the wing in Cumbria
in July.
The
Elephant Hawkmoth (title photo
and larva left) is also common throughout Cumbria because of
the abundance of its foodplants - Willowherbs. This large, pink
and olive-green species is common in gardens at night in late
June and July, especially on Honeysuckle and Rhododendron, but
is often over-looked unless moth lights are used. The large
fully grown larva, having the appearance of an Elephant's trunk,
has spots on segments 4 and 5 - when threatened it withdraws
the first three segments and appears to have huge threatening
eyes. It is a night time feeder but can sometimes be found by
day in September near its foodplants, as it searches for a hibernation
site. The pupa is in a soft cocoon which can be found in leaf
litter or other debris (sometimes in a conservatory or greenhouse).
Much
more local in the county is the related Small
Elephant Hawkmoth (photo right), a species found on limestone
grassland, where its Bedstraw foodplants grow. It is mainly recorded
from limestone areas in the south of the county. It is smaller and more
yellowish than its large relative and has a more prominent and more
wavy pink band at the rear of the forewing. Although not a day flyer,
it is not uncommon to find freshly emerged adults in late May during
the afternoon. Its larva is even more like a minature Elephant's trunk.
The
final resident species in Cumbria is the large Eyed
Hawkmoth. Here it is at its northern limit and although relatively
common it is not often picked up by light traps. The eye spots on pink
hindwings are easily picked out as a diagnostic feature. It is a species
of parks and gardens with Willows and Sallows but will also use cultivated
Apples and Crab Apples as a foodplant.
Because
of their size Hawkmoths can travel large distances and several immigrant
species reach Britain in most years. The only two occurring regularly
in Cumbria are the infamous Hummingbird Hawkmoth and the spectacular
Convolvulus Hawkmoth.
The
smaller Hummingbird Hawkmoth is
well known for its habit of nectaring like a Hummingbird during
the day, often in bright sunshine. Amidst the phenomenal whirr
of wings as it hovers, it is possible to pick out the orange
hindwings and the white-spotted abdomen, but the brown forewings
appear "invisible" as the human eye cannot pick them
out at these speeds. There is also an audible buzz from the
wings. It "jumps" to the next flower with such speed
that it is sometimes hard to spot where it has gone. Its foodplants
are members of the Bedstraw family
but in the garden it is likely to be seen at Buddleia, Petunias
and even Busy Lizzies. When it does stop to warm up in sunshine
it's often hard to spot against stonework (see right) and looks
quite inconspicuous. Studies have shown that the species remembers
good nectar sources, returning at the same time each day to
the same plants. It can appear at any time from April through
to October but more usually in Cumbria in September. In some
years it occurs in number, in other years not at all or very
rarely. There were large influxes in 2000 and 2006 and a smaller
one in 2005. With milder winters, it now over-winters as an
adult in the south west of England.
The
Convolvulus Hawkmoth is large enough,
with a 10 cm wingspan, to be mistaken for a bat in the poor
light of dusk and its larva is something of a monster, being
as much as 11 cm long and 2 cm thick when fully grown. Breeding
in Africa and southern Europe the new brood often migrates northwards
and appears in the UK in September and October, but in Cumbria
it is only recorded in ones and twos in occasional years. As
the name implies, the foodplant is Bindweed but it is said that
in Britain it is attracted well to Nicotiana (although keeping
these in flower until September is not easy). In late September
2006, a well-developed example of the larva tried to cross the
drive of a resident of Baycliffe in south Cumbria. This is quite
a rare occurrence in the UK, larvae rarely going on to develop
to full size here.
Several
other migrant Hawkmoths have been recorded in the last 50 years in Cumbria
but most very rarely or only on one occasion. |