In Britain, this particular species is now found at just 11 small sites in the Lake District and two in north-west Wales. Its population is known to have plunged in the past 15 years.
The inch-wide moth's misfortunes are connected with the decline of the only plant on which its caterpillars can feed, yellow balsam or touch- me-not.
The adults do not emerge from their chrysalis until July, then they mate and lay eggs. This timing ensures that the young caterpillars can eat the plant's growing seeds within their pods; a rich source of protein. They are also disguised as these pods to avoid being eaten by birds.
In the autumn the caterpillar becomes a chrysalis, and remains one through the winter and deep into the next summer.
Its food plant, Impatiens noli-tangere, is a knee-high annual which likes wet ground and just the right quantity of shade. It is an opportunist which grows on bare earth or broken ground in woodland, beside roads, streams, seepages and lakes. It cannot face much competition from other plants.
Several factors have knocked back the balsam; streams drying up or being diverted and road widening and maintenance destroying its habitat. The abandonment of regular, rotational tree cutting and thinning in woodlands has allowed the plant to be shaded out.
The huge numbers of tourists to the Lake District have also done it harm, trampling on it around footpaths, car parks and picnic sites.
Last week, the Government endorsed a rescue plan for the moth and115 other rare or fast-declining plant and animal species. The plans were drawn up by conservation experts from the Government and wildlife charities.
The objective in this case is to identify the insect's precise habitat requirements by the end of next year and to ensure that, by 2000, all the habitats which it could exploit are managed in a moth-friendly way.
A start has been made. Butterfly Conservation, a wildlife charity, is collaborating with the Government's English Nature wildlife arm, Lancaster University and the National Trust, which owns most of the sites where the moth is still found.
Together they are carrying out research, hunting for its haunts and managing the right sort of habitat in ways that will encourage plant and insect to thrive.Reuse content