Family Scarabaeidae - Megasoma actaeon (page 2)

Megasoma actaeon (page 2)

Additional photos of the male M. actaeon, and some images of the female and larva.

Heavy though they are, Megasomas are strong fliers. Like all species of rhinoceros beetles, they have a wide, membranous pair of flight wings folded beneath their hard elytra (wing covers). The elytra of all beetles are actually the first pair of wings. Through evolution, they have been modified into protective structures to cover the abdomen. The fully armored design of beetles is most likely what has allowed them to become the most successful and diverse group of animals on Earth.

Photo courtesy of Milan Polaczyk.

Megasoma actaeon (male) - Image © Milan Polaczyk

This male M. actaeon has only recently emerged from its pupal cell, as is evidenced by its still bent horns. Unlike those of Dynastes, in the pupae of Megasoma the horns are bent toward the body prior to emergence from the pupal skin. After emergence, the horns are pliable and slowly extended outward and hardened. The process of stretching out the horn to its full length can take several days in some instances. Horn extension begins directly after leaving the pupal cell, and during this process it waits in hiding until its horns have fully extended and solidified.

Photo courtesy of Milan Polaczyk.

The female M. actaeon. Although lacking horns, she is rather large, often nearly matching males in body size. She does not have the smooth, black armor of the male. Instead, her exoskeleton is rough. Female dynastines can lay large numbers of eggs, but in the wild, many eggs and young larvae fall prey to predators.

The 3rd instar (L3) larva of M. actaeon. These larvae become extremely large and heavy as they reach the latter stage of the 3rd instar growth phase. They sometimes reach weights of 200 grams, which is the highest known weight for any insect. Unlike those of most other rhinoceros beetles, Megasoma larvae are said to develop best when kept in groups. In the wild, the larvae are apparently gregarious, and it is not unusual to find a dozen or more living in a cluster within the same rotten log. A page is available on the internet which describes the captive breeding of this species. You may access it here.

Photo courtesy of Al O Myrrhina.

Megasoma actaeon (3rd instar larva) - Image © Al O Myrrhina

Back to Megasoma actaeon page 1