Science, Tech, Math › Animals & Nature Stag Beetles, Family Lucanidae Share Flipboard Email Print Getty Images/Biosphoto/Christophe Ravier Animals & Nature Insects Beetles Basics Behavior & Communication Ants. Bees, & Wasps Butterflies & Moths Spiders Ticks & Mites True Bugs, Aphids, Cicadas, and Hoppers Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Marine Life Forestry Dinosaurs Evolution View More By Debbie Hadley Entomology Expert B.A., Political Science, Rutgers University Debbie Hadley is a science educator with 25 years of experience who has written on science topics for over a decade. our editorial process Debbie Hadley Updated January 21, 2020 Stag beetles are some of the biggest, worst bugs on the planet (at least they look bad!). These beetles are so named for their antler-like mandibles. In Japan, enthusiasts collect and rear stag beetles, and even stage battles between the males. Description Stag beetles (family Lucanidae) do get quite large, which is why they are so popular with beetle collectors. In North America, the largest species measures just over 2 inches, but tropical stag beetles can easily top 3 inches. These sexually dimorphic beetles also go by the name pinch bugs. Male stag beetles sport impressive mandibles, sometimes as long as half their body, which they use to spar with competing males in battles over territory. Though they may look threatening, you don't need to fear these enormous beetles. They're generally harmless but may give you a good nip if you try to handle them carelessly. Stag beetles are typically reddish-brown to black in color. Beetles in the family Lucanidae possess antennae with 10 segments, with the end segments often enlarged and appearing clubbed. Many, but not all, have elbowed antennae as well. Classification Kingdom: AnimaliaPhylum: ArthropodaClass: InsectaOrder: ColeopteraFamily: Lucanidae Diet Stag beetle larvae are important decomposers of wood. They live in dead or decaying logs and stumps. Adult stag beetles may feed on leaves, sap, or even honeydew from aphids. Life Cycle Like all beetles, stag beetles undergo complete metamorphosis with four stages of development: egg, larva, pupa, and adult. Females usually lay their eggs under the bark on fallen, rotting logs. The white, c-shaped stag beetle larvae develop over one or more years. Adults emerge in late spring or early summer in most areas. Special Adaptations and Defenses Stag beetles will use their impressive size and massive mandibles to defend themselves if needed. When it feels threatened, a male stag beetle may lift its head and open its mandibles, as if to say, "Go ahead, try me." In many parts of the world, stag beetle numbers have declined due to forest defragmentation and the removal of dead trees in populated areas. Your best chance of seeing one may be observing one near your porch light on a summer evening. Stag beetles do come to artificial light sources, including light traps. Range and Distribution Worldwide, stag beetles number around 800 species. Just 24-30 species of stag beetles inhabit mostly forested areas of North America. The largest species live in tropical habitats. Sources Borror and Delong's Introduction to the Study of Insects, 7th Edition, by Charles A. Triplehorn and Norman F. Johnson.Insects: Their Natural History and Diversity, by Stephen A. Marshall.Stag Beetles of Kentucky, University of Kentucky Entomology Department.