The giant stag beetle, also known as the elephant stag beetle, can be found in the woodlands of North America ranging from Virginia and North Carolina to the northeastern United States. (Arnett, Jr., Ph. D., 1985; Milne and Milne, 1980)
- Habitat Regions
- Terrestrial Biomes
Adult males are 45-60 mm long; females are smaller, around 30-35 mm. This species has a slender, elongated form, with a somewhat flattened back. Adults are reddish-brown, shiny, and have black antennae and legs. Males have a crest above their eyes and a wide head. They are distinguished by their giant antlerlike jaws that may be as long as the head and thorax combined. These jaws have small forked teeth along the inner edge. The females have a narrower head than thorax and much smaller jaws than males. Female elytra are lightly punctate. Giant stag beetles have the segments of their antennae separated rather than compacted like scarab beetles do.
Larvae are white and grub-like, and are characterized by the absence of a 6th segment in the leg. (Arnett, Jr., Ph. D., 1985; Arnold and Drew, 1987; Drees, Ph. D. and Jackman, Ph. D., 1998; Klots and Klots, No Publishing Year; Milne and Milne, 1980; O'Toole, 1986)
- Sexual Dimorphism
- male larger
- Range length
- 30 to 60 mm
- 1.18 to 2.36 in
Giant stag beetle larvae hatch from eggs laid by females on suitable dead trees. They then eat and grow for several years in dead tree stumps. When fully-grown, the larvae pupate for seven to nine months, emerging the following June. After their emergence they live for about three to five weeks more. (Grzimek, 1972; Milne and Milne, 1980; Tweedie, 1973)
Males use their giant jaws to fight for access to females. Individual males try to control a dead tree or stump suitable for egg-laying, preventing other males from mating with the females arriving on the tree. Consequently one male usually mates with multiple females. (Milne and Milne, 1980)
- Mating System
Female stag beetles lay their eggs on dead trees or stumps that will provide suitable food and protection for their offspring. In temperate climates, adults only live for a single breeding season.
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding season
- In temperate climates, stag beetles breed in the summer months.
Eggs laid by female stag beetles are supplied with a small amount of nourishing yolk, but the beetle larvae hatch quickly, and receive no additional care. Male stag beetles do not care for their offspring.
- Parental Investment
Males use thier impressive manibles in defense, as well as to compete with other males. Males compete with each other for access to females.is attracted to lights at night. They can also sometimes be seen flying around dusk.
When males are challenged or forced to defend themselves they rear up using their forelegs and spread their jaws. This stance is mainly a bluff though, as their jaws can only pinch rather than inflict a painful bite.
Both males and females have difficulty getting upright if overturned because of their top-heavy heads and flattened backs.
Adults and larvae can be found in large colonies in burrows and rotted out logs. Adults can make noise by rubbing wing-covers or their legs together. (Burton, et al., 1968; Cottam, Ph. D. and Zim, Ph. D., 1956; Milne and Milne, 1980)
Communication and Perception
Adult elephant stag beetles, like most stag beetles, feed on sugary liquid foods, mainly sap leaking from wounded trees, aphid "honeydew" secretions, and ripe fruit. They cannot chew food. The larvae feed on wet, decaying wood, probably getting nutrition from the wood and the fungi and microbes that are decomposing it. (Milne and Milne, 1980; O'Toole, 1986)
- Primary Diet
- eats sap or other plant foods
- Plant Foods
- wood, bark, or stems
- sap or other plant fluids
- Other Foods
Economic Importance for Humans: Positive
These large beetles are collected and raised by hobbyists. In the wild they can be important agents of wood decomposition.
Economic Importance for Humans: Negative
Though startling if found unexpectedly, these big beetles have no significant adverse effects on humans. They can pinch hard if handled carelessly, but only bite in self-defense. (Drees, Ph. D. and Jackman, Ph. D., 1998)
- Negative Impacts
- bites or stings
This species is uncommon, but not believed to be in need of special conservation efforts.
Sara Diamond (editor), Animal Diversity Web.
Scott Teakell (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- bilateral symmetry
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
active at dawn and dusk
a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
An animal that eats mainly plants or parts of plants.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- internal fertilization
fertilization takes place within the female's body
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
- native range
the area in which the animal is naturally found, the region in which it is endemic.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
having more than one female as a mate at one time
- seasonal breeding
breeding is confined to a particular season
offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- sexual ornamentation
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
movements of a hard surface that are produced by animals as signals to others
uses sight to communicate
Arnett, Jr., Ph. D., R. 1985. American Insects: A Handbook of the Insects of America North of Mexico. New York: Van Nostrand Reinhold Company.
Arnold, D., W. Drew. 1987. "The Stag Beetles of Oklahoma(Coleoptera: Lucanidae)" (On-line). Accessed February 18, 2001 at http://digital.library.okstate.edu/OAS/oas_htm_files/v67/p27_29nf.html.
Borror, D., R. White. 1970. A Field Guide to Insects: America North of Mexico. Boston: Houghton Mifflin Company.
Burton, J., I. Yarrow, A. Allen, L. Parmenter, I. Lansbury. 1968. The Oxford Book of Insects. Oxford: Oxford University Press.
Cottam, Ph. D., C., H. Zim, Ph. D.. 1956. Insects: A Guide to Familiar American Insects. New York: Western Publishing Company, Inc..
Drees, Ph. D., B., J. Jackman, Ph. D.. 1998. A Field Guide to Common Texas Insects. Houston, TX: Gulf Publishing Company.
Grzimek, D. 1972. Grzimek's Animal Life Encyclopedia Vol.2 Insects. England: Van Nostrand Reinhold Company.
Klots, A., E. Klots. No Publishing Year. Living Insects of the World. Garden City, New York: Doubleday and Company Inc..
Milne, L., M. Milne. 1980. The Audubon Society Field Guide to North American Insects and Spiders. New York: Alfred A. Knopf, Inc..
O'Toole, C. 1986. The Encyclopedia of Insects. New York: Equinox (Oxford) Ltd..
Tweedie, M. 1973. All Color Book of Insects. London: Octopus Books Limited.