Hey there!

Right on, nope I haven't heard anything from them yet, but will keep an eye and ear out for it! It could be one in the same, sounds like some species of Sphinx (commonly referred to as 'Hornworms') but I wouldn't be able to tell 100% without a photo or the host plant =/

Then again, the other that comes to mind with that description might be the Xuthus Swallowtail, which would be found on various Citrus. This cat looks like bird droppings until the last instar, at this point it has yellow and black eyespots and looks similar to a hornworm...I know I have a photo of my own somewhere around here...Ah well, a link'll have to do =]

Good luck with the Plum.s! I have just a few of my own starting now, just a matter of waiting to see what colors I've got. Have cuttings from a few different sources and no idea which are which =/ Gonna be a surprise lol.

Got plenty of Cannas right now, if you're interested in those at all just let me know. Probably got right around 8 different variations.

Take it light and talk to ya later on, here are some links to take a look at if you're interested n have some time =]

~Dave

Sphinx Moths of Hawaii
http://www.hear.org/starr/hiinsects/images/family/lepidoptera_sphingidae.htm

Butterflies of Hawaii
http://www.asahi-net.or.jp/~ak5t-kmn/hawaii/hawaii.htm

Papilio Xuthus - Xuthus Swallowtail
http://en.wikipedia.org/wiki/Papilio_xuthus#Caterpillar