Ladybird larva. Coloured scanning electron micrograph (SEM) of the larva of a 24 Spot Ladybird - Subcoccinella vigintiquattuorpunctata.The adult 24-spot is a small ladybird, usually 3 to 4 mm long. It has the quintessential ladybird shape, quite domed with the sides forming a smooth curve from head to pronotum to wing-cases. Larvae are 4 to 6mm long andare covered with branched spines. These spines are also present in the pupa, enabling the pupa to secrete noxious alkaloids as a defence against predators. Magnification: x50 when printed at 10 centimetres wide.