Small Striped Flea Beetle Phyllotreta undulata

This is one of a number of similar species of black flea beetles with bold yellow stripes down their elytra. On many the outer edge of the yellow stripes are indented near the middle, whereas the sides of this one (and a couple of other species) are straighter.

I initially experienced some difficulty separating this species from Phyllotetra vittula and my first example initially identified as undulata was, I now believe, Phyllotreta vittula. I think the following individual still stands as undulata - the humeral angle is better-defined (this is more subtle than I expected), the central black elytral stripe broadens towards the rear, the yellowy stripes are shallowly indented along the outer sides and the base of the yellowy stripes lacks the angular extension.

Phyllotreta undulata, Wendling Beck Environment Project (Norfolk, UK), 30th April 2022