ladybirds

[Ser]

is there such a thing as a poisonous ladybird?

[Cetti]

This is from the UK Safari site: If you pick up a Ladybird, it will release a yellow fluid that is pungent and slightly caustic. This is actually blood which comes out of it's body through it's legs. It has a very bad flavour and once a bird has tasted this, it will rarely try to eat another ladybird. They don't sting, although they can give you a nip if they accidentally mistake you for a greenfly. Their bright coloration is a warning to other animals that they taste bad. In fact they have very few natural enemies.

[New Forester]

The yellow stuff is irritant too. If you get on your skin, it feels sore and itchy (so some people think they've been bitten). Even worse in your eyes! You generally have to upset the beetle to make it produce the yellow fluid -- picking it up is usually OK if you're gentle. Usually you get it if the animal's been squashed or pinched, perhaps in clothing.