Ladybirds - a good year

So many ladybirds this spring and now into early summer!  I had the 'traditional' seven spot on my peas and encouraged it onto my hand for closer inspection. It didn't want to have anything to do with the broad bean tips where black harlequin ladybirds were tackling juicy looking black fly, and flew off.
My neighbour's plum tree has an aphid infestation and is a veritable ladybird motel. We thought there might be some inter-specific mating going on (see tradtional-looking type on top, top, and black one on top, below!)
Having looked at the ladybird survey I see that they are likely to all be Harlequin ladybirds, the common melanic (black) form and the usual orange one.  They can have up to 21 spots which fuse in different ways, so they can look completely different within the species.  This is an invasive alien species that outcompetes native types.  They still eat aphids, though.