The large goat moth ‘Cossus cossus’ has a fascinating life-cycle.
Occasionally found in more open habitats, such as woodland edges, gardens and parks, the larvae have powerful mandibles to burrow in the trunks of various trees. In the New Forest this is often oak, where the life cycle may take five years.
Sometimes sap exudes from larval exit holes in the trunks and this smells like fermenting alcohol. The nocturnal adults are seldom seen.
More likely, the huge larva will be seen wandering on tracks before finding a suitable spot to go underground, where they pupate in a strong cocoon the following May; sometimes this is formed in bark.
The goat moth-infected trees attract a wide range of interesting, often rare insects to sap runs, including parasites of the goat moth larvae.
Adult moths fly in June to July. The full grown larvae exit trees mainly between August to October and the larval chambers are said to smell ‘goat-like’.
Photos: Russell Wynn