A few years ago I was given some unwanted seedlings of Dog rose, Rosa canina. I planted them in the garden with my usual carelessness, and they've grown fast, forming a mini-thicket! That'll teach me!
However one of the many resulting delights, quite apart from the beauty of the rose itself, is the presence of the Large Rose Sawfly, Arge pagana, which has found my thicket.
This is a very attractive sawfly which has a bright orange-yellow body. It has a slow-ish flight
so is easily spotted in the garden. What has fascinated me about this insect is its egg-laying process.
The female uses her ovipositor to cut a little channel in a rose stem, in which she then deposits her eggs from which the larvae eventually emerge and feed on the rose leaves.
I spotted a female just starting to lay eggs around 8pm one evening recently. .
I kept an eye on her and went back into the garden from time to time, to see how she was getting on. To my astonishment she was still going at about 10pm, having created an incision about 5 mm long. I marvelled at the slow and steady progress - I'd no idea it would take that long.
Next morning I looked again and saw the channel with the eggs in, like the one below.
I'm now enjoying watching the colourful larvae scoffing the foliage; doubtless some of them will in turn be lunch for the many hungry birds visiting the garden.
