Page 38 - Silver Lakes June 2021

NATURE

DRAGONFLIES AND DAMSELFLIES

AT ST LEGER DAM

Text by Anthony Cavanagh, Photos by Anthony and Sue Cavanagh

ave you ever watched the tiny
flying insects hovering over a still
Hbody of water such as a dam, a
pond or even a puddle? In this miniature
world there is a whole microcosm of life
that struggles to survive whilst preying
on anything smaller than themselves
and trying to reproduce as quickly
as possible in their short lifespan.
Dragonflies and damselflies live in this
precarious environment and can often
be seen darting around the periphery of
St Leger Dam.
There are 164 known species of dragonfly
and damselfly in South Africa with the
largest measuring some 100mm in
length and having a wingspan of around
115mm. Most species are, however, very
much smaller. Damselflies are much
more slender in build and their eyes are
widely spaced on their heads. Their wings
close against their abdomen when they
settle. Dragonflies by contrast are more
robustly built. They hold their wings at
right angles to the body when they settle

Broad Scarlet male
and their eyes join together at the top of Adult dragonflies and damselflies often
their heads. fall victim to birds such as rollers and bee-
eaters and other unfortunates fly into
These insects are often brightly coloured spiders’ webs with fatal consequences.
and various hues of blue, red, green, Both species lay their eggs in water, the
yellow and brown dominate. Both species quantity of eggs varying from dozens to
are predatory and many hunt on the hundreds depending on the species. Water
wing, catching small flying insects. Some temperature often affects hatching and
species are able to fly forwards, backwards some eggs laid late in the summer season
and straight up and down while some of may only hatch into nymphs during the
the larger species are capable of bursts of next season. The nymphs then enter the
speed up to 35km per hour. Other species larval stage and remain in the water for
are ambush hunters and lie in wait for some two months in the case of small
their prey. Dragonflies snatch their damselflies and up to a year for the larger
victims encasing them in their legs, then species. The nymph sheds successive skins
bite their prey with their well-developed as it grows until finally it emerges from
mouth parts. the water where it metamorphoses into

Anthony photographing at St Leger dam

36 INTRA MUROS JUNE 2021