Japanese stag beetle Beetles are the most plentiful family of animals known. It is estimated that one out of very four animal species on earth is a beetle. When British biologist J.B. S. Haldane was asked by a group of theologians about what he thought about God as creator, he replied that God had "an inordinate fondness for beetles." The name "beetle" comes from the Anglo-Saxon word for "to bite." [Source: Douglas Chadwick, National Geographic, March 1998]
Beetles are found almost everywhere in the world. Some live in ground, some lives live in trees and some live in the water. Thus far abut 350,000 species of beetle have been described in the scientific literature but the true number of beetle species may be in the millions. One tree in Peru yielded 650 beetle species.
Ancestors of beetles had two sets of wings like dragonflies. As they evolved one set of wings developed into a hard shell that gave the insects protection from predators. The number of beetle species increased dramatically when flowering plants became the dominate form of vegetation on earth. Many beetles eat flowering plants and their diversity is related to the diversity of flowering plants. In some cases groups of beetles that eat flowering plants are 1,000 times more diverse than beetles that eat other kinds of plants.
The scientific name for the order to which beetles belong, Coleoptera , means "sheathe wing." All beetles have four wings. The front pair form a thick, hard, shiny, protective shells that opens when the beetle wants to fly. The back pair are used for flying. They ingeniously fold inside wing covers and spring open when the wing coves are opened. Most beetles don’t use their wings much: often just to make quick escapes like flying chickens. Beetle wings are delicate and probably would be damaged if they were not protected by the covers.
Some beetle species are quite colorful. Colors of all sorts, combinations and hues are found in their hard, armorlike front wings---their shells.
Websites and Resources on Insects: Insect.org insects.org ; Insect Images.org insectimages.org ; BBC Insects bbc.co.uk/nature/life/Insect ; Insect and Arachnid entomology.umn.edu/cues/4015/morpology ; Wikipedia article Wikipedia ; Virtual Insect home.comcast.net ; National Geographic on Bugs National Geographic ; Smithsonian bug info si.edu/Encyclopedia_SI/nmnh/buginfo ; Entomology for Beginners bijlmakers.com/entomology/begin ; BugGuide bugguide.net ;
Websites and Resources on Animals: ARKive arkive.org Animal Info animalinfo.org ; Animal Picture Archives (do a Search for the Animal Species You Want) animalpicturesarchive ; BBC Animals Finder bbc.co.uk/nature/animals ; Animal Diversity Web animaldiversity.ummz.umich.edu ; International Field Guides media.library.uiuc.edu ; animals.com animals.com/tags/animals-z ; Encyclopedia of Life eol.org ; World Wildlife Fund (WWF) worldwildlife.org ; National Geographic National Geographic ; Animal Planet animal.discovery.com ; Wikipedia article on Animals Wikipedia ; Animals.com animals.com ; Endangered Animals iucnredlist.org ; Endangered Species Resource List ucblibraries.colorado.edu ; Biodiversity Heritage Library biodiversitylibrary.org
Kinds of Beetles
Some species of beetles are excellent swimmers. Other are superb diggers, runners, and flyers. There are species of beetle that can walk on glass surfaces, skirt across water, prosper in the mouthpiece of bees, communicate by rubbing their wings against their abdomens, lay their eggs in dead rats, and disguises themselves as dung balls to attract prey. Some beetles piss like a dog by lifting one leg. Others use their poop to plant trees.
Tiger beetles can scurry along at two feet a second, which means if they were enlarged to the size of a race horse they would move at 250 miles per hour. Some species of burying beetles can lift 200 times their own weight. In a forest in Indonesia in the 1850s, Alfred Russel Wallace was amazed by what he thought was the fragrance of roses in a rain forest. He was even more surprised when he discovered the smell came from tiger beetles not flowers.
Unusual beetle species include wingless black-and-orange trilobite beetles from Borneo; the bizarre four-inch-long-horned beetle from French Guiana. Some species of ladybug practice cannibalism and allow a bacteria to enter their eggs that kills males but allows females to survive. They female in turn eat the male embryos. Blister beetles can cause the skin to peel. They are the source of Spanish fly.
Some beetles have some unusual features. Bombardier beetles have a highly efficient combustion chamber in a gland near their anus that shoots boiling-hot chemicals at would-be predators. The Melanophila beetle, which lays its eggs in freshly burned wood, has evolved a structure that can detect the precise infrared radiation produced by a forest fire, allowing it to sense a blaze a 100 kilometers away. This talent is currently being investigated by the U.S. Air Force. [Source: Tom Mueller, National Geographic , April 2008]
There are about 150 families of beetles. The scarab beetle family contains more than 30,000 species. The largest family, the weevils, contains 60,000 species counted so far and is the largest family of living organisms on earth. They have large mouthparts usually affixed to the tip of their snout that allows them to bore deep holes and deposit their eggs eve in the hardest seeds or nuts. They are also often also excellent fliers. See Boll Weevils, Cotton, Fabric.
Stag Beetles and Japan
Stag beetles are large beetles with fearsome-looking mandibles that are nearly as long as the beetle's body and resemble the antlers of a stag.
Stag beetles and rhinoceros beetles mop up tree sap. Only male rhinoceros beetles have horns. Male stag beetles have longer mandibles than females.
Japanese are fond of buying and collecting beetles and keeping them as pets. They are particularly fond of stag beatles, fearsome- looking black insects with large jaw-like mandibles, and rhinoceros beetles, similar to stag beetles except the have a large "horn" protruding from their thorax above their head.
Stag beetles possess mandibles that are nearly as long as the beetle's body and resemble the antlers of a stag. Varying in lengths from 0.6 centimeters to 8.5 centimeters, they are smooth, black or reddish brown. Males are larger than females and have enlarged mandibles that are used in fights over females. There are about 1,000 species of stag and rhinoceros beetles in the world, with 20 species in Japan. Generally found in the forests and mountains around rotted logs and oak trees, the Japanese species are between 5 centimeters and 8 centimeters in length and hibernate in the winter.
In the wild, stag beetles are active mostly at night. Despite their large size they, like all beetles, can fly. Eggs are laid in decaying tree stumps or roots. Larvae live in rotten logs or are buried in the soil, feeding on rotten wood. Once they are large enough they pupate. Adults either do not feed on drink fluids such as nectar or sap, which they can smell.
In November 2007, new species of stag beetle---the takaneruri kuwagata beetle or Platycerus sue Imura---was discovered in Japan. Males have a turquoise metallic luster; females are bronze colored. Almost immediately after its discovery catching the beetle was banned and the place where it was found was kept secret after a pair of the insects was put for auction in the Internet for $1,000.
Dung beetles work by themselves or in pairs to build perfect balls of dung larger than themselves and then stand on their front legs and push and roll the balls of dung backwards with their back legs and then bury it. The dung beetle selects the least fibrous bits of dung for its ball. They bury tons of material a year, fertilizing the soil by entrapping nitrogen underground where I can be utilized by plants.
Dung beetles are thought to have got their start by feeding on dinosaur dung before moving on to mammals. Today they occupy an important environmental niche, moving dung underground, where it can be used as fertilizer for plants and can sprout seeds rather than staying aboveground where it can attract flies, diseases, beastly smells or be washed away and fowl waterways.
Some species cut out pieces of dung and roll it away for private consumption. Others dig under a deposit and draw it into their tunnels. The tunneling species have evolved horns which the use to protect their tunnels from other males.
Dung beetles bury the dung to keep it away from competitors and provide a safe place for their offspring to grow up. Females lay their eggs in the dung and the larvae fed on the dung until they develop into beetles.
The beetles do their work mostly at night When a ball is complete, a beetles moves it as quickly as it can to a shelter so the ball is not stolen by another beetle. Studies have shown that dung beetles are able to strike out in a direct line to their shelter when the moon is full but have difficulty finding the way on moonless nights. Further studies shows the beetles oriented themselves not to the moon itself but used moonlight to navigate their way.
Dung beetles belong to the Scarab beetle family along with leaf chafers and Hercules beetles. Members of this scarab beetle family are extremely varied in their shape, size and color. Their length varies from 0.2 to 17 centimeters. The end of their antennae have a distinctive club made of three to seven flat moveable plats, Males of many species have an enlarged head or horns to fight over mates.
The Egyptians worshiped scarabs as symbols of immortality because they entered the ground and later emerged again as if resurrected. Scarabs were buried with mummies and small statuettes of scarabs were carved from valuable stones.
Male and Female Dung Beetle Behavior
Male and female scarab beetles pair up and jointly gather dung and roll it and pat into a ball on which the female lays her fertilized eggs, The male occasionally tries to attract an extra female or two. If he gets caught though he can end up in big trouble. In one experiment a mated male was set lose while the female was tethered nearby. The male quickly seized the moment and released phonemes signaling that he was available. When the female was released she knocked the male on his back and rolled home into a ball of dung.
Some dung beatles have huge horns that take up to 15 percent of their body weight. Those that have the horns tend to be the dominant males that stand guard over tunnels with an egg-laying female inside. Many males of species that have horns fail to develop them when they are deprived of nutrition at a crucial stage of their development. Instead they have only small bumps.
Sometimes small sneaky males have sex with females sequestered in their tunnels while the large dominant male isn’t paying attention. Some small males achieve this by digging tunnels that connect with the one the female is in. Others hang around outside the entrance and try to slip in when the dominant make isn’t looking.
Text Sources: Mostly National Geographic articles. Also Life on Earth by David Attenborough (Princeton University Press), New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
Last updated March 2011