Sexual dimorphism differences between adult populations of Rynchophorus ferrugineus and Scyphophorus acupunctatus (Coleoptera Curculionidae) from Sicily

Abstract

The Red Palm (Rhynchophorus ferrugineus) and Agave (Scyphophorus acupunctatus) weevils have been introduced into Sicily during the past three years. These two weevils are damaging severely canary date palms (Phoenix canariensis) and century plants (Agave americana) in many areas of the island. The sexual dimorphism of these two weevils is well documented in the literature. Sexual dimorphism differences observed in adult populations of the two weevils from Sicily are provided to facilitate the identification and sexing of these two pests by local agricultural specialists. Rhynchophorus ferrugineus males have a shorter body than that of females and a rostrum with numerous and straight setae that are lacking in the females. Medial margins of male protibiae with long setae, which are short and sparse in the females. Schyphophorus acupunctatus males have a longer body and more deeply concave first abdominal sternum than the females. Males also have a convex pygidium, which is fiat in the females.