Bramble Sawfly

Size caterpillar/larvae about 18mm. A bit of a disappointment that one of the cutest caterpillar I have seen is actually not a lepidoptera but a hymenoptera. I found lots of these active animals crawling on tree trunks and under leaves. They have very distinctly forked tails, are shiny green with a yellow stripe along each side of its body. The head is orange-brown, looks like a bald head, with cute little eyes. The larvae wiggle their tails when they are feeling threatened. The spelling of this species is quite tricky. http://www.brisbaneinsects.com/brisbane_sawflies/BrambleSawfly.htm got the name wrong, and http://lepidoptera.butterflyhouse.com.au/none/xanthophilax.html seems to have corrected their spelling mistake in the text but not the page address. The original document can be found at http://www.biodiversitylibrary.org/page/4490830#page/139/mode/1up (very recommended read). The spelling is indeed P. xanthophylax (with y and ax as an ending). It is noteworthy that Philomastix macleaii (Westwood), as researched in the article and cohabitating with P. xanthophylax has vanished taxonomically. Actually, with a lot of searching I discovered that someone has changed it to Philomastix glabra. It seems extremely dubious and taxonomically wrong. Froggat 1890 erected the genus Philomastix. In 1918, he synonymised his own Philomastix glabra with Perga macleaii Westwood 1880. Accordingly, he used the correct term Philomastix macleaii (Westwood). It is my opinion, that ALA should change P. glabra and reverse synonymy. Maybe I missed a publication and some meddlings. It would just help if taxonomy used would be more transparent and helpful in resolving conflicts. How can biodiversity data be collected if the underlying taxonomy is vague and wrong? Update 6/7/2017: The animals in the gallery Striped Xenica have been misidentified. I will move them here. Here is what I wrote there: Size about 18mm. I found a few of these cute caterpillars in bushland on a young tree. They were crawling up quite fast. At some stage a fly joined my photo target, was visibly interested in the caterpillar. My identification is highly speculative. It is unlikely that it is correct since this species has no records as far north. I matched it to http://lepidoptera.butterflyhouse.com.au/nymp/kershaw.html. There it says that later forms can have a forked tail. The body of this specimen is bright green with a neon green line along the whole body. Three front leg pair are enlarged, making it quite fast. Tail is forked and shows little dots. Its head looks like a helmet. It is brown and roundish with a dark eye spot, making it look like an extra-terrestrial visitor. Body shows fine hair and hair bundle. Shoulder and back of the body show single black spots. Update 20/7/2017: One rule is to never try to find a species. Nevertheless, I ventured into nature with the only goal to find the mama and maybe papa of this caterpillar. I found plenty of juveniles. They have grown, are huge. They seem hungry as the canopy of some Red Ash have been consumed and the caterpillars head downwards. While some are still finding food, others seem to discolour. I doubt that they manage to change a tree. It is true indeed that they are very food specific, and I got the hang of locating their host tree. No grown ups was showing however.