So although most Ladybird species are very consistent in their colour patterns, with just one or two varieties, there is one species, Harlequin Ladybird, that is tremendously variable. This recent introduction is our largest species, and many varieties have a distinctive W shaped mark on the thorax. The lower 2 in your photo show this. The third individual looks the same size, whereas if it had been a 2 spot would have been considerably smaller. 3 Harlequins, and presumably 2 males trying to dislodge each other for mating rights.