Why do we call a ladybird a ladybird? First of all why the 'lady' and secondly why a 'bird'? And if you look up in the OED, the historical dictionary, its first record of the word 'ladybird', you'll find a 1674 glossary of southern English dialect. And the author describes how the dialect word 'bishop' is the southern English term for the little spotted beetle commonly called the Lady cow 'or the Lady-bird.' And then 'ladybug' followed, and eventually 'ladybird' settled. But bot terms are preceded by this 'cow-lady' and 'ladycow' which is even stranger than a ladybird. There is a parallel going back even further of 'God's cow', which may have been the same insect. Neither a bird nor a lady, if you start with the 'bird', there is some idea that it might be an alteration of 'budde', which in Middle English was applied to quite a few different forms of insect. However, it's generally considered that 'bird' was simply a reference to the bug's winged nature and its flying abilities. 'Lady', apparently refers to the seven spots of the Coccinella septempunctata, the common (UK) native ladybird, that is being threatened by the harlequin ladybird. The spots are said to symbolise the seven pains of the Virgin Mary in the RC faith, which involved the flight to Egypt and the crucifixion of Christ. And so 'ladybird' was simply 'Our Lady's bird.'
