Dynastes tityus, the eastern Hercules beetle, is a species of rhinoceros beetle native to the Eastern United States. The adult's elytra are green, gray or tan, with black markings, and the whole animal, including the male's horns, may reach in length. The larvae feed on decaying wood from various trees.
Taxonomy and names
Dynastes tityus is known by a number of common names, including eastern Hercules beetle, elephant beetle and ox beetle. It was first given a scientific name by Carl Linnaeus, in his 1763 work Centuria Insectorum, where it was called Scarabaeus tityus; when Linnaeus' genus Scarabaeus was divided into smaller genera, S. tityus was renamed Dynastes tityus.
Description
Adults of both sexes are wide, and males are long, The horns are used in battles between rival males competing for a mate; Occasionally, both elytra may be a uniform mahogany color, or one elytron may be pale with dark blotches, while the other is a plain mahogany color.
The eastern Hercules beetle has a multilayer body structure in which the exact composition has not been determined. The known components of the insect cuticle are chitin fibers and a proteinaceous matrix. They fuse with each other and build an ordered structure which can store energy to protect the wing and body. When the elytra appears deep brown under the high humidity environment, it can better defend the beetle from attacks and accidents. Furthermore, the elytra is more apt to regular protection and attack when it has the yellow-green color. This lineage has been further dispersed by the Transverse Volcanic Belt and the Sierra Madre del Sur into eastern and western species in North America.
The larvae of eastern Hercules beetles live in decaying wood. They prefer to reside and develop within the large cavity at or near the bases of the tree through which they can tunnel into the soil. The adults are observed to live in the vegetation and under moist leaf-litter. The fallen leaves and logs can protect the beetle from predation risks. They are also found to live on ash trees where the trees help them attract and locate mates.
Life history
Mating can last up to 50 minutes in D. tityus. The larvae are large C-shaped grubs with white bodies and chewing mouthparts, No further parental care behavior is reported.
The beetles undergo metamorphosis, which includes egg, larval, pupal and adult stages. Females lay the white-yellow eggs inside the soil during the summer. Eggs have an incubation period of about one month, followed by three larval instars, which refer to molting stages of the larvae. The complete development may take up to three years in the wild. While D. tityus inhabits the eastern United States, Dynastes grantii (the western Hercules beetle) live at higher elevations in Arizona, New Mexico and Utah. Several species are found in Mexico with Dynastes hyllus found as far north as Tamaulipas.
Interaction with humans
D. tityus possess elytra that are light and strong, and the purpose of elytra is to protect the beetle’s hindwings. Their unique and beneficial elytra has inspired applications to the human world.