Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Wednesday, January 30, 2008

Hairy "Tiger Moths"

Have you ever grabbed a Moth, to throw it outside, at night, to stop it crashing into the TV, or your head when you are in bed, just underneath a low reading lamp? If so, then, like me, you will know that most Moths are hairy creatures. You will have ended up with a pile of dust on your hand - fine dust. In fact these are scales which brush off onto your hand, or the window, if a moths has been endlessly bashing the window, trying to escape.

There is a theory that Moths and Butterflies (both in the order Lepidoptera - which means scaly wings) evolved their scales as a defence mechanism against spider webs, as it apparently allows them to slip away from the web (well - sometimes, anyway.)Anyway, Wikipedia tells me that moths are much hairier than Butterflies, probably as an insulation device, because they are active at night (when it is colder than in the day). Indeed Butterflies generally have finer scales on their wings, and smoother bodies. Contrast that concept with this little Crimson Tiger Moth (Spilosoma curvata). It is wearing a very fashionable fur collar - (see also the Ermine Moth further down the page). In this photo (here below), you can see its "collar" is covered in long hairs. But the bright red part of its abdomen (visible in the top photo) is also extremely hairy (but with shorter hairs).
In case you did not notice this little Moth had died - long ago - and was dessicated, lying in the bottom of the window (which it why it was so co-operative in posing on its back). Here is the same species of moth, outside my front door, on 4 October last year. So, it is a springtime Moth (the peak season for moths in Robbo is autumn).This next little Moth is another type of "Tiger Moth" - a "Lichen Tiger Moth" (partly named from the colours, obviously). But it is in a specialist group of moths, the caterpillars of which are said to feed only on Lichen (hence the first part of the name). They are described as pupating in a thin cocoon, formed of felted hairs, which is stuck onto a tree trunk or a wall. In this case, an adult is sitting beside a cocoon, of another individual, which I find puzzling. Why would it do that? Is it waiting for a potential mate to hatch out? The cocoon was on a star picket fence post. It is Asura cervicalis. This moth is active in summer. This photo was taken last week.
This particular group of moths gets a special mention as being mimics, in a system known as Mullerian Mimicry. The idea is that these moths are unpalatable, or possibly even poisonous. But they share their colouration with other insects (wasps and bees) which are similarly unpleasant to eat. According to this theory, it benefits both groups of insects if birds and other predators learn (quickly) not to interfere with creatures which look like this.

Here is another moth which is closely related to the Crimson Tiger Moth (above). I have found these moths to be quite "tame" and allow themselves to be encouraged to sit on one's fingers. This is in the same genus as that moth. This one is Spilosoma canescens. Its common name is "Light Ermine Moth" which at least fits with its "fur coat" which it appears to be wearing. I love the colouring of these Moths, with the wonderfully bright upper side of the abdomen, and the front legs. The black dots along the side are a nice piece of design too. A really pretty creature.

The specific name "canescens" comes from the Latin word "cana", which apparently means grey, and also hairy. I had wondered why it looked like it was referring to dogs - maybe that is why, if the early dogs were wolf-like, they would have met both meanings. But this Moth is named for the original meanings of "cana", not for any resemblance to dogs, as such - it is just a coincidence.You can see from this photo that this Moth is quite similar, in the distinctive hairiness, to the "Crimson Tiger Moth" above. This is another springtime Moth - the photo was taken in October last year.

It is unclear if these Spilosoma species are "introduced" or "universal" - but I have found references to this one (above) in Norway and Japan. The known plant foods (listed on the Australian Moths web pages of both species above), are all introduced plants. So, I conclude that at least this one, and possibly both, are introduced moths. But neither is listed as a known "pest species" on the "Pests and Diseases Image Library" website, an Australian Government initiative.

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