Larval morphology and biology of two species of Aphodius (Plagiogonus) from the Iberian Peninsula (Coleoptera : Scarabaeidae : Aphodiinae)

The larval morphology of Aphodius (Plagiogonus) nanus Fairmaire, 1860 and A . (P.) arenarius (Olivier, 1789) are described and redescribed, respectivel y. The common characters of both species, and the specific diagnostic chara cters are provided and discussed. The most important morphological characte rs of the larvae of Plagiogonus Mulsant, 1842 are the longitudinal alignmen t of the anterior setae of the stipes, the spatulate form of the posterior- lateral setae of the glossae of the hypopharynx, the slight development of the anal lobe slit, the form of the epitorma of the epipharynx, the slight sclerotization of the pternotormae and the relative length of second antenn al segment. A key to the larvae of both species of Plagiogonus is presented along with life history data and the preferred food of these species. This study shows that A. arenarius and A. nanus feeding habits are closer to sa prophagy than to coprophagy.