Backlit Hairy Caterpillar

These caterpillars are often found on big tree trunks. Wonder what they eat? Moss? Taken at night in Singapore.

Quote from www.wildlifeinsight.com/Insigh…
As the most important part of a caterpillars defence against predators is not to be seen, many are the same shape and colour as the twigs and leaves around them. In order not to give themselves away many will remain motionless and hide during the day, only coming out to feed at night.

Caterpillars may be covered in varying amounts of hair known as setae. Although many species rely on camouflage as a form of protection against predators and have few obvious hairs other species are excessively hairy. This hair acts as a defence against birds and predatory insects such as parasitoid wasps which find it difficult to penetrate beyond the hairs to lay eggs beneath the caterpillar’s skin.

It is notable that some of the hairiest caterpillars are those most often seen basking out in the open such as the Garden Tiger (Arctia caja) and Fox Moth (Macrothylacia rubi) above right) indicating that birds find their hairy bodies unpalatable.

We are fortunate in Britain that there do not appear to be any caterpillars that can cause any fatal reactions to humans coming into direct contact with them as in some tropical rain forests. Nevertheless, handling caterpillars should be kept to the minumun both for the benefit of the creature and the handler.
The tail-spurs on some British caterpillars such as Hawk-moths may appear threatening to predators but in reality they are harmless. However, the hairs of some caterpillars such as the Pale Tussock moth (Calliteara pudibunda) (above left) and the Brown-tail Moth (Euproctis chrysorrhoea) can be extremely irritating and when plagues of Brown-tail caterpillars occur pest control measures may be undertaken by public authorities concerned for public safety. The similar Yellow-tail moth is shown above with the Brown-tail having brown hair tufts, less obvious red lines down its back and two more prominent red spots on the lower body segments.