Last week we visited pseudoscorpions, one of the tiniest arachnids in Belize, measuring roughly 8 mm in length. This week we flip the hero of the story and meet an insect almost 150 times larger than the pseudoscorpion, the gigantic elephant beetle. These titans are not encountered on a regular basis, but good fortune smiled on our Belizean crew when we erected a broad white cloth on a large stanchion and illuminated the cloth with powerful lights after dark. The attraction of night-flying insects to light is legendary and within hours of sunset hundreds of rainforest insects found their way to the lighted cloth and the surrounding vegetation.
After colliding with a student while on its way to rendezvous with an illuminated cloth, this giant elephant beetle landed on a lawn. While delivering a gentle touch to this marvelous scarab, the beetle displayed an interesting behavior of dipping its body toward the ground and seemingly rotating its impressive horn in the direction of an offending finger. Perhaps this tilting behavior is designed to protect the beetle’s delicate underbelly while the impressive horn parries the attacker away. Caught someplace between terror and joy, bold students couldn’t resist wearing and holding one of the largest insects on earth. The chance to see and hold this marvelous creature is a memory not to be forgotten.
While one student stood marveling at the panoply of six-legged wonders, she was pelted by an enormous rhinoceros beetle nearly the size of a softball that collided with her back. Rhinoceros beetles are members of the scarab beetle clan, and are renowned for their remarkable size and the large horns that adorn the males. Her visitor was an elephant beetle, one of the five largest beetles in Central and South America. Males use their horns in fierce battles with other males for access to mates and food. Some say the large central horn of the rhinoceros beetle resembles the trunk of an elephant, hence its name.
Female elephant beetles lack horns and can be much smaller (left) than enormous horned male beetles (right).
Adult beetles dine on fallen fruit and exudates from trees, and their offspring dine on decomposing vegetation like the remains of fallen trees. Beetle larvae are shaped like the letter “C” a characteristic common throughout the scarab clan. Three years may pass before they reach maturity, while the adults live only three or four months. An encounter with this goliath of the insect world is memorable. Tips of its powerful legs bear sharp claws which embed in clothing and flesh, making the removal of the beetle from a human an awkward and uncomfortable challenge. Placing a finger aside the giant causes it to tilt toward the groun,d apparently to prevent the offending finger from poking beneath its body. Perhaps this behavior has evolved to thwart lateral attacks by predators to the less protected belly of the beetle.
Imagine how big elephant beetle larvae will be when fully developed. These two are only about halfway grown.
Our oversized visitor eventually arrived on the top of the white cloth near the bright light where it rested beyond the late hour that students and faculty retired for the night. By dawn the next morning, the elephant beetle and other visitors to the lights had departed to continue their assignments in the rainforest. The chance to see and hold this marvelous creature remains a memory not to be forgotten.
On the steps of a pyramid at Caracol, students from the University of Maryland explore the wonders of tropical rainforests and Mayan civilizations. Image: Luis Godoy
Acknowledgements
Bug of the Week thanks the adventurous students and faculty of BSCI 339M, Belize: Tropical Biology and Mayan Culture, for providing the inspiration for this episode. Special thanks to Adèle and Erron Murphy for allowing me to record and share their encounters with this remarkable beetle. Special thanks to the staff of the Toucan Ridge Ecology and Education Society for allowing us to learn about insects in their rainforest reserve.