Bug Identifier
Stag Beetle
Community identification

Stag Beetle

Lucanidae (family)

Order & Family
Order: Coleoptera, Family: Lucanidae
Size
Depending on the species, stag beetles can range significantly in size, usually from 2 cm to over 8 cm (0.8 to 3.2 inches) in length, excluding mandibles. Males are typically larger than females and possess much more prominent mandibles.
See this bug in the Encyclopedia

Natural Habitat

Stag beetles are typically found in woodland areas, forests, and gardens where there is ample decaying wood, such as old logs, stumps, and dead trees. This is crucial for their larval development.

Diet & Feeding

Adult stag beetles primarily feed on tree sap, decaying fruit, and honeydew. Their mandibles are not used for biting but rather for defense and mating rituals. Larvae feed on decaying wood.

Behavior Patterns

Adult female stag beetles lay eggs in decaying wood. Larvae feed on the decaying wood for several years, going through multiple instars. Adults are primarily nocturnal and are attracted to lights. Males often engage in fights using their mandibles to compete for mates.

Risks & Benefits

Stag beetles are harmless to humans; they do not bite or sting. Their large mandibles, especially in males, can look intimidating but are not used aggressively towards people. Ecologically, they are beneficial as decomposers, playing a vital role in breaking down deadwood and returning nutrients to the soil. They are also considered indicator species for healthy woodland ecosystems. In some regions, certain species are endangered or protected.