The terminalia of the superfamily Scarabaeoidea (Coleoptera): specific glossary, dissecting methodology, techniques and previously unrecorded sexual dimorphism in some difficult groups

The terminology used for the morphological structures of the abdomen as well as male and female genitalia across the superfamily Scarabaeoidea is discussed, based on a literature review across the group. Issues relating to the orientation of the male terminalia and potential homologies between the 'genital capsule'- and 'spiculum gastrale'-bearing taxa are discussed and standardisation of terminology pertaining to some ambiguous terms is proposed. A Scarabaeoidea-specific glossary is presented, and synonyms across the literature are given. Schematic illustrations of the abdomen and terminalia are provided. Some new morphological structures are here described for the first time. A standardised dissection protocol for male and female Scarabaeoidea is proposed. Sexually dimorphic structures in the abdomen of Pleurosticti (Dynastinae, Rutelinae, Melolonthinae and Cetoniinae), Glaphyridae, Phaenomeridinae, Passalidae and Omorgus (Trogidae) are described and illustrated for the first time, providing future workers with the possibility to determine the sex of specimens based on external characters without the need for dissection.