1.
Introduction
Dragonflies (Odonata)
are widespread hemimetabolous
insects.
They are amphibiotic their larvae are strongly associated with the
aquatic environment,
while adults are flying
insects connected with
water throughout their
lives, especially during
oviposition.
According to the type
of inhabited microhabitat, there are two
groups of dragonflies’
larvae - one living on
sand or gravel as well
as decomposed organic
matter, and the second
one being phytophiles
living mainly among
macrophytes.
Those microhabitats
are mainly found in running waters, both natural
and anthropogenic, like
rivers, streams, drainage ditches or channels.
Equally preferable are
different kinds of standing waters like lakes,
ponds, bogs, swamps,
as well as tanks in gravel
pits, quarries, clay and
peat excavations. But
in some cases, tiny and
temporary water reservoirs, like phytotelmata
seem to be enough.
2. Discussion
What we call
an
extreme place to live
is relative, but for this
review the extremely
challenging habitats,
which require special
adaptations from dragonflies living there,
were selected.
The first species is semiterrestrial
Uropetala
carovei, which inhabits highland spring-fed
bogs in New Zealand
(Wolfe 1953, Corbet
1962, Silsby 2001). It
drills little burrows in the
43
seepage area, often with
two openings or several ‘chambers’ on the
basis (Fig.1). However,
there was no case of
finding more than one
larva in single burrow
(Wolfe 1953). Larvae
live in the chambers
embedded in a fine silt
with their caudal plates
above. The burrows are
constructed in such a
way as to allow water
infiltration to the inside,
so that they are provided with the necessary
moisture to breathe
through their rectal gill.
Therefore, Uropetala
larvae can spend even
several months out of
the water (Wolfe 1953,
Corbet 1999). That
construction can take
various forms, dependent on several factors.
Firstly the larva lives
just below the water
level, but older instars
are found at the greater depth (Wolfe 1953).
Uropetala dragonflies