Polyarthron philbyi, a very rare member of Prionini tribe endemic to Saudi Arabia, has been described from Dalgan (Riyadh, SA) by André Villiers in 1968 [▽]. The biology of this local crepuscular and nocturnal desert species is unknown, adults can be caught on very warm late evenings and during nights (using light traps) [❖].

Body length:	14–24 mm
Life cycle:	2–3 years [?]
Adults in:	September–November
Host plant:	unknown, probably polyphagous in roots of desert plants
Distribution:	endemic to Saudi Arabia

The depicted male beetle was attracted by light in Riyadh environs (Saudi Arabia) on October 20, 2025.

Collected by Petr Papoušek

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[▽]
Villiers A.:
Coléoptères Cerambycidae d'Arabie.
Bulletin du Muséum National d'Histoire Naturelle de Paris(2ème série) 39 (5): 846-850, 1967. [download ]

Holzschuh C.:
Cerambycidae (Coleoptera) of Saudi Arabia: Part II, Prioninae and Cerambycinae.
Fauna of Saudi Arabia 13: 110-129, 1993. [download ]

Rapuzzi P. and al Dhafer H.:
The Cerambycidae fauna of Saudi Arabia (Coleoptera).
Revue suisse de Zoologie 131 (1): 177-217, 2024. [download ]