Family Scarabaeidae - Dynastes hercules (page 4)

Dynastes hercules (page 4)

On this and the next page is shown a rare and unique sequence of photos which depict a large male D. hercules as it emerges from its pupal form. Ordinarily, this entire process would take place within the darkness of a fully enclosed pupal cell. However, here we are actually able to see this transformation happen since the pupa has been removed from its natural cell and placed in an appropriately sized box in which it is still able to emerge properly. These photos were generously provided by J. Lai.

The skin of the pupa has become very thin and papery, and is being slowly shed. Pupas which are nearly ready to reach the adult stage darken and develop a slightly wrinkled appearance just prior to the emergence of the beetle.

Dynastes hercules (male) emerging - Image © J. Lai

The pupa has now flipped over so that it is right side up, and several of the insect's legs are now free of the pupal skin. The large, downward curving flaps visible on the sides of the pupa are the structures from which both the the elytra and the flight wings will emerge.

The shining black thoracic horn, with its characteristic tooth-like dorsal projections, is now visible. The sheaths which enclose the beetle's horns are more robust in form than the actual horns which they cover.

The beetle has now almost completely emerged from its pupal skin. Note that the elytra are currently very light in color. They will eventually darken and harden to the typical brown colour with numerous black spots, but this process will take some time to complete.

The beetle has completed emergence from the pupal skin, and is now in the process of straightening and folding its elytra and flight wings. The flight wings are some of the most delicate structures of the beetle's body, and the insect must slowly expand them and fold them beneath the protective elytra.

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