ID of larva and behavior

[loboclerk]

Found this caterpillar, about 1 inch. Think I went too near, it kept crawling around, even onto a tree trunk as the leaf was leaning on it. Anyone familiar with this?

#1 top view
http://pix.bay.to/albums/macro-2011-04-24-rifle-range-road/DSC_6702_600.jpg

#2 side view
http://pix.bay.to/albums/macro-2011-04-24-rifle-range-road/DSC_6714_600.jpg

#3 it kept moving.. i gave it a soft blow/whiff as it stops bugs momentarily sometimes, and it contracted, while squeezing bubbles of water through each spike. Quite a cute sight. Apologies for the blur pic, the water lasted less than 5 seconds and I didn't expect it at all.

http://pix.bay.to/albums/macro-2011-04-24-rifle-range-road/DSC_6717_600.jpg

Is it some defence mechanism?

Thanks in advance

[horace2264]

Looks like the caterpillar of a day flying moth, Pompelon marginata.
A google search will yield a number of sites featuring the beautiful adults.

[loboclerk]

Thanks Horace, yes looks exactly like the larva of day-flying moth.

Now to figure out the water bubble phenomenon... wonder if it happens on other caterpillars?

[horace2264]

You might want to be very careful with the caterpillar and avoid contacts with those liquid droplets. This day flying moth belongs to to the Zygaenidae family, and the liquid droplets are a part of their defense mechanism. For more information on this, please refer to page 43. of this Australian book (http://books.google.com.sg/books?id=R8OgFq9gfwgC&printsec=frontcover&dq=Zygaenid+moths&source=bl&ots=6T5EzFaPOZ&sig=lu504oFueXCchlG7Gu1_bfEnUrQ&hl=en&ei=EQ21TaOLNIXsrQe79InIDQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CB0Q6AEwAQ#v=onepage&q&f=false) on this moth family.

[loboclerk]

Yes, suspected that it was part of it's defence mechanism, have never physically touched a caterpillar before though. Last time I accidentally touched one at AHBT when I didn't notice it, and it gave a stinging pain for about half a day.

Thanks for the warning and info!