malaeng chi pa-khao (แมลงชีปะขาว)
for ‘Mayfly’ or ‘Dayfly’,
i.e. a family of aquatic insects the belong to the order
Ephemeroptera, which is part of the Palaeoptera, an ancient group of
insects that also includes
Akin to the latter groups, mayflies also spend most of their lives
as nymphs in fresh water,
until they hatch into a fully-winged, terrestrial adult. Like
dragonflies and damselflies,
mayflies moult with wings that
−while at rest− do not fold flat over the abdomen, but instead are
held upright, like those of most
At the posterior part of the abdomen,
both with the nymphs and adutlss, are three distinctive long,
thread-like tails. Mayflies get their name for the fact
that they hatch in large numbers from spring to autumn, though not
necessarily in May. They are unique among insects, in that they moult a second time after already having acquired functional wings.
The first stage after moulting into a
fully-winged terrestrial adult
is knows as
subimago, while the final
stage is called
imago. Though they physically resemble each other,
usually sexually immature and the wings
are murky and fringed with tiny hairs, whereas with in the final
of moulting), the wings are
clear and transparent, and the Mayfly is now ready for mating. However, this final instar usually lives for
only a very short time and has consequently been nicknamed Dayfly.
At this stage, its flight is often erratical and it easily falls
into the water, where it becomes an easy food source to many fish.
The final Mayfly instar is also used by fly fishermen, who refer to
it as a dun. In
English also commonly known as Shadflies and in Thai these flying insects may also commonly be referred to
by the English corresponding term mayflies (เมย์ฟลายส์).
See List of Thai Insect Names.
See also WILDLIFE PICTURES.