Moths of the Amazon
Superfamily - THYRIDOIDEA
Family - THYRIDIDAE
subfamily - SICULODINAE
Tribe - SICULODINI
Siculodes aurorula, Arima valley, Trinidad ©
There can be few butterflies or moths as weird as this creature
which I discovered in the rainforests of Trinidad. While walking
along a trail my attention was caught by what appeared to be a dead
leaf that seemed to have fallen and landed on a broad green leaf. A
spider appeared to be squatting in the middle of the dead leaf but
somehow it all looked a bit too symmetrical.
Upon closer examination I realised that the 'dead leaf' was in fact
a moth, and that the 'spider' was its body and legs. It adopted a
bizarre Buddha-like posture, with its body propped up vertically by
its long stilt-like legs, and its wings outstretched like a bat.
This wonder of the natural world moth had a strange mesmerising
effect on me. It is an incredible example of camouflage - perfectly
disguised as a dead leaf, complete with transparent windows that
simulate the nibblings of insects, and dark blotches that could
easily be mistaken for leaf mould.
For several years
I was completely mystified by the insect, but it was eventually
identified by Mike Shaffer of the British Natural History Museum as
aurorula, a member of the Thyrididae.
This specimen was the first ever recorded in Trinidad.
My photograph of the living moth finally revealed the purpose of its
incredibly long legs. These had long puzzled entomologists who had
studied the museum specimen. The moth needed them so that it could
prop itself up in this very odd upright posture. The pose is almost
threatening. Why would a moth evolve such a strange posture? Perhaps
when viewed from the front it might appear so scary that it would
frighten off a small avian or reptilian predator? Perhaps it simply
needs to raise itself clear of the substrate to avoid getting stuck
to it when the leaves are wet with rain?
Thyrididae consists of about 1000 species found in the lowland
tropical rainforests of the Afrotropical, Oriental, Australian and
neotropical regions. They are split into 4 subfamilies: Striglinae,
Thyridinae, Siculodinae and Charideinae.
The Siculodinae is
the largest subfamily with over 420 species arranged in 3 tribes:
the Argyrotypini, Siculodini and Rhodoneurini. The majority of
species are brown or reddish, and cryptically patterned to resemble
dead leaves. The Siculodinae typically have falcate forewings with
circular hyaline areas that simulate the holes eaten in leaves by
beetles and moth larvae.
has only been recorded on
very rare occasions, with just 2 records from Brazil, one from Guyana
and one from Trinidad. It undoubtedly also occurs in Venezuela and
tropical rainforest in Trinidad, Venezuela, Guyana and Brazil.
Other than the fact that it is
nocturnal, little is known. The moth could easily be handled,
suggesting that it remains stationary and relies on disguise for
protection from predators, rather than flying to escape.