Rose Sawfly Arge pagana

Sawfly are included with Wasps rather than Flies since they are of the "Hymenoptera" order (Bees, Wasps and Ants) with four wings.
They are stockier than most wasps, with little waist between thorax and abdomen and have caterpillar-like larvae. Females have a serrated "saw-like" ovipositor to cut plants/leaves.

Rose Sawfly
Rose Sawfly
The Rose Sawfly has a black head and thorax and an orange-yellow abdomen.
Rose Sawfly
Rose Sawfly
Rose Sawfly
Its clear top wings have a black border to the outside edge.
Rose Sawfly
Rose Sawfly
Rose Sawfly
Rose Sawfly Larvae
Rose Sawfly Larva
Rose Sawfly Larvae
Sawfly larvae look like caterpillars (of butterfly/moth) but have six or more pairs of prolegs (9 or more pairs of legs), whereas a caterpillar has five or less pairs of prolegs (8 or less pairs of legs).
Rose Sawfly Larvae
Rose Sawfly Larva
Rose Sawfly Larvae
The larva in the centre top in the above left photo (and elsewhere in others) is at a younger stage of development (earlier instar) than those with dark spots.
Rose Sawfly Larvae
Rose Sawfly Larva
Rose Sawfly Larvae
Rose Sawfly larvae are known for synchronised feeding behaviour, such as lifting their tail half together and assuming similar shapes in unison.
Rose Sawfly Larvae on roses
Rose Sawfly Larvae on Rose Leaves
And this is what they have done to my roses . . .