Page 17 - BBC Wildlife Volume 36 #12
P. 17
WILD DECEMBER
Hidden Snow fleas have a
fairly widespread
N distribution across
the UK– only the
south-west seems
to miss out.
here I was, in
December – I had
pulled over in a patch
Tof heathy woodland to
answer a call of nature when I
caught sight of movement on
the ground by my feet. It was NICK
winter – what could it be? BAKER
On closer inspection, I
realised I had found my first Reveals a fascinating
(and, to date, only) snow fleas, world of wildlife that
Boreus hyemalis. The frigid we oten overlook.
winter months are not known
for entomological exuberance. diagnostic feature of this family e cold and its cell-rupturing
Wings are a ‘no-no’, unless SNOW FLEA of insects – a long ‘face’. In ce crystals, they have the ability
you’re the toughest of midges reality, this is an elongated o supercool. They lower the
or moths. That’s probably why rostrum, or beak, with freezing point of fluids in their
the snow flea, one of our most mouthparts at the tip. cells, using special proteins and
bizarre insects, is wingless. A fly that can’t fly sounds olyhydric alcohols, so that ice
Despite its name, it isn’t like an oxymoron. Yet it doesn’t rystals don’t form. Being
a flea or a fly. It belongs to stop the snow flea getting ctive in cold conditions is
the scorpion flies, a group of about, which it does by walking worth it – there is less risk
insects, mostly denizens of or by jumping up to 5cm in a f meeting predatory insects.
summer hedgerows. Britain single bound. Though it has no
has three other species of obvious external adaptations for Winter romance
scorpion fly, all bedecked with the saltatorial task of leaping, he pair I had disturbed were
picture-frame wings. The males the snow flea does have long pretty much the only things
possess a curious swollen legs and the use of an moving in the frozen landscape,
genital capsule, which is held DID YOU elastic protein called so got my full attention, but
at the tip of their slim abdomen KNOW ? resilin. This acts like I noticed something odd. The
and curls backwards, producing an internal catapult emale – easily recognised by
Snow fleas stay active
a threatening look, reminiscent down to around –5°C. and is the same stuff er long ovipositor (egg-laying
of a scorpion’s tail. They particularly like that gives actual ube), which gives her abdomen
The snow flea lacks pretty mossy heaths, moors fleas their bounce a sharp point – was on the back
and wooded
wings or outwardly distinctive – together with snow of the male.
areas.
genitals. But it has the other fleas’ small size (around It’s not strictly true that male
5mm), it explains at least now fleas have no wings –
part of the common name. they are reduced to strange,
IN THE BLEAK MIDWINTER The rest of the moniker spine-like projections – and
probably refers to the fact that this male was busy using his
Some moths shun summer and become active now.
the species is usually noticed like a large pair of sexual
On all but the coldest of nights, fleas, these insects supercool against snow. These insects ongs. He had rotated them
Illustrations by Peter David Scott/The Art Agency may reveal and lure in the males occasionally gathering on of the female, holding her in
live mainly in mossy subnivean
ehind his thorax, and clamped
a late-night country
to avoid the dangers of
hem about the head capsule
(below the snow) habitats,
drive in December
freezing. Meanwhile,
the female moths
position for mating.
the surface. They don’t need
moths in your
are wingless bags
snow but they do best in
These amazing little insects
headlights.
of eggs with legs.
are an entomological highlight
regions with harsh winters.
They climb up tree-
These are
of winter, for those determined
As insects, they are
trunks and bushes
winter moths,
enough to look.
ectothermic (cold-blooded),
Operophtera
brumata, and they’re
by emitting pheromones
Rather than be at the mercy of
all males. Like snow
s a naturalist, author and TV presenter.
December 2018 through the chilly air. so cannot generate body heat. NICK BAKER BBC Wildlife 17
