Farmers, Warriors, Builders: The Hidden Life of Antsat the Smithsonian's National Museum of Natural History
Hercules Beetles
Dynastes hercules
Hercules beetles, also called rhinoceros and unicorn beetles, are among the largest beetles in the world.
Distribution and habitat
They are mainly found in tropical rainforests in Central and South America, but live as far north as Mexico as well as on some Caribbean islands.
Physical description
There is significant sexual dimorphism in Hercules beetles—it is easy to distinguish between males and females. Adult males (shown at upper left) have an upper horn that protrudes forward from the thorax and a lower horn that protrudes forward from the head, while females (shown at right) lack horns altogether. Males can be up to six and a half inches long, including the horns. Females often have a greater body length but are not as long overall. Males have black heads and a set of forewings that can be shades of green, brown or black, while females are entirely brownish black.
Lifespan
Hercules beetles have a total life cycle of about a year and a half. They live underground as larvae for ten to 16 months, but only live for three to four months as adults.
Behavior
They are generally nocturnal but are sometimes active during the day, especially when looking for a mate. They are strongly attracted to light.
Feeding
Adults feed on sweet fruits, tree sap, and decaying plant matter. Larvae develop in or around rotten logs and eat decaying wood.
Reproduction
Hercules beetles typically mate during the rainy season, at which time the males become extremely aggressive. In certain species of Hercules beetles (though not the ones from Central and South America), males duel with one another in order to win mating access to females. To do this, they use their horns to lift their opponent up and knock him to the ground.
At the Zoo
The National Zoo's Hercules beetles live at the Invertebrate Exhibit. A rearing program was started in December 2005. In summer 2007, the zoo’s first generation adult beetles started laying eggs.
Did you know?
Pound for pound, Hercules beetles are the strongest animal in the world. Some can lift as much as 850 times their own weight. 
more animal records
