HUGE numbers of Red Admiral butterflies have been seen all over the Isle of Man in recent days, filling gardens and glens with a blaze of red and black.

With their favourite flower - buddleia - now in full bloom all over the Island, there appear to be more Red Admirals now than at any other time of the year, no doubt encouraged by the warm weather.

The butterflies are taking the opportunity to gather nectar from flowering shrubs and trees. They feed on nectar from flowers, with buddleia undoubtedly the favourite. In the autumn they feed on over-ripe fruit such as plums and apples.

Red Admirals also hibernate and can often be found hiding in a quiet corner of a house, occasionally emerging in mid winter when central heating tricks them into thinking it’s spring.

After hibernation in the winter, adults have a strong urge to fly northwards, bringing immigrants from the Continent throughout the summer. By mid-August they start to return south, leading to a build up in southern England in autumn.

During the summer females lay single eggs on the growing tips of nettles. After a week or so, the caterpillars hatch and each spins a tent around itself by fastening a young leaf double with silk.

Four weeks later caterpillars pupate in a similar ‘tent’. Adults may hibernate in England, usually choosing an exposed site such as a tree trunk, and many perish. 

Caterpillars are bristly and dark with a pale yellow stripe running down each side. They also benefit overgrown gardens because they eat stinging nettles.

Photo: Bill Dale