Crane
flies are among the animals which cause the most panic in a bedroom, apart
from probably spiders, that is. Attracted by the light, they fly in the
window and start to flap against lampshades of the main light or the bedside
light...apart from this they do no harm at all. Craneflies are merely
large flies. They do not feed as adults, nor do they bite or sting. The
female lays eggs in the ground, where the larvae feed on vegetation, sometimes
causing damage by gnawing at the roots of plants.
Crane
fly larvae may also appear in thatch. They normally live in damp earth,
and so it is only in old, damp, mossy thatched roofs that they can thrive.
They themselves do little damage in a roof that has already suffered,
but it becomes more serious if rooks or other birds discover this source
of food and start to pull at the thatch in order to reach the larvae.
These
rather leggy flies, sometimes referred to as Daddy Longlegs, have a tendency
for the legs to break off when handled. Many crane flies are only mosquito-sized,
but all can be recognised by the V shaped suture on the thorax together
with a lack of ocelli. Larger species generally rest with the wings extended:
smaller species generally fold their wings flat over the body and often
bob up and down on their legs when at rest, hence their alternative name
of "bobbing gnats". The female abdomen is pointed for laying
eggs into the ground or other materials. Some females are wingless and
can be seen on house walls in late autumn. Adults may lap nectar and other
fluids but do not feed much. Larvae live mainly as scavengers in the soil
or decaying matter, often under water. The larvae, pictured above, are
often referred to as "leatherjackets".
Looking
at the picture below that is of two craneflies mating, the female is recognisable
on the right by her more swollen abdomen, this is because she is full
of egss, as yet unfertilised. The abdomen tapers to a stylus like ovipositor,
frequently mistaken for a sting. The male genitalia include a pair of
claspers which grip the female genital valves but in order to do so the
males abdomen has to be twisted through 180°.
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