I saw a 'fly'...

Turnip Sawfly (Athalia rosae)

The flowers of various umbellifers in the garden always attract plenty of insects to their buffet, and on a recent evening, this Mugwort (Artemesia vulgaris) was no exception. Among its diners was a new one for me, though not for the garden, since Mike saw some last year – a Turnip Sawfly (Athalia rosea), also known as Cabbage Leaf Sawfly. This handsome wee beastie is pretty distinctive. Its orange thorax (the part of the insect just behind the head), abdomen and legs are set against its black head and "shoulder pads", and it has a dark line down the leading edge of its wings. Each of its tibial joints is black at the upper edge, making its legs look banded. Males have pointy abdomens while those of the females are rounded. It's resident and reasonably widespread in England and Wales, but much less common in Scotland. Large numbers also regularly migrate north from the continent. The larvae feed on crucifers, so given the vast fields of Oilseed Rape (known as canola in the US) flourishing on one side of the garden, it isn't hard to guess where this one came from. Such feeding can become problematic for farmers if the sawflies reach big enough numbers. Adult Turnip Sawflies are nectar feeders and more general in their tastes, though they prefer the flowers of umbellifers and crucifers. They fly from April through October, so we'll probably be seeing others as the summer progresses.