Similar burrows are
drilled by the other
Petaluridae
larvae,
for example Petalura
gigantea, which was
described by Tillyard
(1911).
In addition, a few fully
terrestrial species, like
Hawaiian Megalagrion
oahuense, are known.
Its habitat is a rhizome mat of ferns like
Dicranopteris linearis or
Gleichenia sp. growing
on the steep hillsides
(Corbet 1962, Silsby
2001).
The
larvae
breathe using atmospheric oxygen thanks
to the high humidity of
the air. Moreover, they
have a few morphological adaptations to
prevent excessive loss
of moisture - they are
stocky and hairy, their
body is strongly shortened and their caudal
Fig. 1. The burrow of Uropetala lamellae are squat and
carovei – type with several thickly covered with
chambers (Wolfe 1953, modi- setae (Corbet 1962).
fied)
also use their burrows
for hunting. They show
nocturnal activity, when
the entrances of their
burrows are even less
visible. The darkness is
used to hunt for small
arthropods by taking
them by surprise (Wolfe
1953, Winstanley &
Rowe 1980).
44
Larvae,
which
inhabit reservoirs periodically drying out,
have to deal with similar problems. Australian
Synthemis eustalacta
occupies summer-dry
pools and is able to
survive in shallow, dry
sand up to 10 weeks
without being moistened. After this period
of time the larva is so
dry that in its first contact with water it floats
on the surface (Tillyard
1910, Corbet 1999). It
is probably also caused
by the structure of the
hydrophobic wax covering the body surface (Corbet 1999).
However, there are not
many drought-resistant larvae. Common
adaptation for droughts
is a modification of
voltinism (Suhling et
al. 2004, Corbet et al.
2006). Odonata often
use the strategy of
accelerating the development cycle in order