Larval morphology of a Palearctic Rutelini, Parastasia ferrieri (Coleoptera, Scarabaeidae), with discussions on their feeding habits

Rutelini is one of the largest tribes of Rutelinae, widely distributed but primarily in the New World. Recently, both larvae and adults of Parastasia ferrieri had been discovered in Liaoning Province of northeastern China from the Palearctic realm. The third-instar larvae of P. ferrieri were described using light and scanning electron microscopy in order to discover more morphological characters for larval taxonomy. The larvae of P. ferrieri exhibit remarkable features, including four protuberances on labrum, no helus on epipharynx, two scissorial teeth on each mandible, five stridulatory teeth plus a blunt protuberance on each maxilla, and the obtuse claws on the thoracic legs. The correlation between morphological features and feeding habits is briefly discussed.