Springbrook Research Centre
Luminous caterpillars
These super-mobile caterpillars are hard to catch , rarely seen above ground, and due to
their bioluminescent properties have been mistaken for glow worms in the past.
They are found as juveniles at a depth of up to approximately 100mm in the surface layer
of humus-rich soil beneath forest leaf litter.
When they reach maturity in the larval stage of their development as per the photo/s
below, they emerge to the surface and graze on and under the rotting leaf litter and have
the extraordinary ability to quickly burrow under leaf litter and softer soils to hide.
They live mainly in forest litter although occasionally are spotted high up in trees
grazing on rotting bark and fungus .
I first noticed them high up in trees in 1998 and mistook them for glow worms as the
bioluminescence is similar in colour to, although not as bright as glow worms.
On closer inspection the tail glows continuously and when disturbed and in motion the
head, tail and the whole digestive tract of the caterpillar exudes bioluminescence in the
blue/green spectrum not unlike a neon tube.
They inhabit areas on our property that produce luminous forest litter.
These same forest floor areas are heavily cultivated by the local scrub turkeys and the
caterpillars may unfortunately be a food source for the turkeys.
This luminescence of large areas of the forest floor has been a popular attraction for our
visitors for many years now and it will be interesting to determine whether the
caterpillars glow because they eat the luminous fungus. There may also of course be no
connection between the fungus and the caterpillar and further work is required.
10-12-2001
The first luminous caterpillars for
2001 have emerged and are currently 5mm in length. Specimens are currently being observed
and further information will follow as they progress toward maturity.
04-03-2002
The extreme dry weather due to 5 of the
past 6 months yeilding well below average rainfall seems to have prematurely ended our
observations of luminous caterpillars this season. Although late rain is now occurring it
apprears that the cycle of emergence has been broken.
22-08-2002
 |
Here we see a 5mm long
luminous caterpillar grazing on rotting leaf material.
In it's juvenile form it is slower moving , only glows from the tail and appears to spend
most of it's life underground in large numbers. |
With an above
average rainfall this month subterranean emergence of the luminous caterpillars is
prominent with above average numbers being found in the rainforest areas.
30 specimens averaging 5mm in length have been introduced into our underground facility in
a simulated forest-floor environment for further observation.
29-12-2002
Pupae
A Luminous pupa has developed
in our underground centre and is possibly one of our luminous caterpillars. The pupae has
been isolated in a container awaiting hatching. For comparison two more pupae have been
excavated from 150mm below the forest floor in humus rich soil under the leaf litter and
have been isolated in a second container containing forest floor material.
 |
26-01-03
My fault, due to pressure of work in
other fields the contents of the pupae have escaped from the container of forest litter.
I was hoping that our luminous caterpillars were the larval stage of our local species of
Firefly viz: Atyphella atra Lea (Lampyridae: Luciolinae) that are common at Springbrook
during the late spring to early summer period, although expert external advice assures me
that they are not.
I am still not convinced as the development of the larvae seems to coincide with the
annual emergence of fireflies in the Springbrook Research Centre firefly observation area.
30-07-2004
It is possible that the caterpillars are the larval stage of a
luminous moth described as such by early settlers of this area in correspondence circa 1914. This
moth has yet to be sighted in recent times.
22-11-2005
The luminous caterpillars we
have been observing appear to be in two different sizes at this time. There are both
juvenile (5mm length) and mature (16mm length). Whatever they transform into upon maturity
would suggest that they either have multiple emergences at different times of the year, or
a larval lifespan exceeding twelve months.
Controlled environment
Each of the above larva when extracted from the soil is covered in a mucus-like casing
inside which it appears to live while underground. The tube breaks away but remains
attached around the larvae as they are separated from the soil.
Perhaps, as with glow worms, this mucus-like casing provides an insulated environment for
the larvae.
The mucus-like material itself is both strong, elastic and water-resistant.
The larvae can be encouraged out of the mucus-like casing undamaged by swirling in shallow
water and then draining the water off.
It has been observed previously that prior to pupation the larva leaves it's mucus-like
casing and rises to the surface where it appears to graze on forest leaf litter.
Note 23-11-2006
Latest information = The larvae have
been identified as the larval stage of an as yet unidentified MOTH.
G.Maguire
Springbrook Research Centre
|
