The Stag Beetle
The Stag Beetle is an amazing creature but it's still not fully understood even by experts. For example, although we know they have a life cycle of up to seven years, we aren't really all that sure what they eat once they've transformed from larvae into adults. Some studies indicate they might feed on tree sap, others that they just don't eat full stop. Perhaps both are true, depending on the individual beetle.
The Stag Beetle is Britain's largest terrestrial beetle, with males growing to 7cm and females to 5cm. The males have large mandibles that look a little like the antlers of a deer, hence its common name. Females don't have such big mouth parts. The antlers are used for territorial fighting between males; they try to grab each other and then throw the opponent. In theory both males and females could nip you and draw blood but this rarely occurs and they're not at all dangerous.
Stag Beetles need old, established woodland. As larvae they feed on rotting tree matter. They used to be found all over Europe but, because of the gradual loss of woodland, they are now extinct in some countries, such as Denmark. The Stag Beetle is considered to be globally threatened and is listed as a priority species in the UK Biodiversity Action Plan. It is a protected species through its listing in Schedule 5 of the Wildlife and Countryside Act 1981 (as amended).
The lifecycle of the Stag Beetle starts with the females laying their fertilised eggs, which are about 2-3mm in diameter, in damp earth, near rotting wood (it seems favoured species are Oak, Ash and Elm). The eggs hatch into larvae, which develop below ground in decaying tree stumps or partially buried deadwood and feed on the rotting wood over a period of up to five years. The larvae pupate in the autumn and emerge the following spring; mating occurs in June and July and the females lay their eggs in the autumn.
