Biology

The small heath is quite a conspicuous butterfly despite its size. They fly only when the sun is shining and can be seen throughout the summer months. The butterfly produces two broods, a fact that explains its long flight period, from April to October if the weather allows. Its foodplants are grasses, especially the fine grasses of the Fescue and Poa genera. The eggs are laid in June and the caterpillars are a clear green in colour with a darker green stripe down the back, which helps to camouflage them from predators. The chrysalis is yellow-green and is suspended from the underside of a grass stalk or blade. Eggs laid in June usually hatch into adults in August and provide a second population of butterflies, some of which will overwinter to breed the following spring. Some pupae, however, do not hatch until the next year.