Several species live in our gardens, nearly all helping in the fight against aphids. They'll eat their way through several dozen in a single day. The largest and most common is the 7-spot ladybird, with seven black spots on its bright red elytra. It lays many yellow, skittle shaped eggs on aphid covered plants. The resulting blue larvae join the adults at the feast. Each larva will demolish several hundred aphids during its 3-week development. Then it attaches itself to a leaf and turns into a pupa.