I'd be inclined to believe the offspring would be black since red is recessive. (blue eyes vs brown eyes)

Hi

I think maybe they are "harlequin" the way you have described them , could be various colours

Gregor Mendel where are you when we need you? Since insects reproductive arrangements have a lock and key type of fit, the mating pair were either a any port in a storm sort of affair between two different species with no reproductive success. Or a perfect fit between the same species with reproductive success including a predictable result in markings in the offspring without much variation throughout successive generations barring any mutations. This was a very good question.

Thank you all for the interesting replies. One more question: is the Harlequin ladybird the foreign invader?

the harlequin is the invader. but there are black british native ones. There is substantial research to show the female selects her mate based on his colour. the darker the colour the better he is.

The development of colour is determined by several genes and isn't as clear cut as senior school syllabuses [or is it syllabi?] would lead us to believe.

Thanks again everybody. I appreciate all the information.

I was looking in the same direction as Seaburngirl. It all comes down to genetic coding. There could be broad variability in the offspring such as we see in a litter of kittens. I actually studied this very situation in Biology but with fruit flies.

Sounds like one of those dreaded 'probability' questions that always floored me in maths!

Some facts about the Harlequin and its variability:

http://www.cabi.org/isc/datasheet/26515