Alternatively, the name might be derived from Hypharpax, a genus of Australasian ground beetles (Coleoptera: Carabidae: Harpalinae) established by Alexander Macleay in 1825.

[4] Phibalosoma hypharpax is a stick insect species characterised by its slender, cylindrical body devoid of spines.

The description is based on a single male specimen, as at the time of its original collection, the female of the species had not been documented.

The head is relatively large, oval-shaped, and slightly flattened, featuring pale patches on the front and sides.

[5] The thorax maintains the slender, cylindrical form of the body, with the mesothorax measuring about 10 lines (2.1 cm) in length.

The forewings, or tegmina, are small and narrow, approximately 4 lines (0.85 cm) long, and possess a prominent raised ridge (carina).

A noticeable ridge (called a keel) runs around the egg from top to bottom, interrupted only by a special plate-like structure on one side.

[5] It appears to be widely distributed in the tropical lowland and mountainous regions of the island, but absent in the northern portion.