Phoridae

Phoridae phallus

Studies and illustrations of Phoridae phallus are scarce, and generally each author adopts completely different terminology to name its different parts. Although there is no consensus in respect to the terminology and to the homology of the plates, most authors that studied this structure concluded that it is an important source of taxonomic information (Brown 1987a, 1987b; Nakayama 2012; Naumov 1985; Venturi 1966).

Proliferation of different terms and using no terms at all for some sclerites will not help to achieve good homology hypotheses. Therefore, the main six works with phallus description were studied and a table with the equivalent terms is proposed (Table 1).

Author / year Brown, 1987 a, b Venturi, 1966 Nakayama, 2007 Gotô, 1984 Naumov, 1985 Disney, 1999 The position, connection and special similarity of the phallic plates illustrated in these works were analyzed in this effort of terminology uniformization. Some difficulties in understanding the correspondence of terms were found as the authors studied different genera and sometimes illustrated different views in different level of detail. Many more morphological studies are needed to clarify these problems, but a uniform terminology represents the first feasible step towards homology hypotheses.

The terms used in this work are the same as Brown (1987a, 1987b, 1998), which follows the terms advocated by Emden & Hennig (1970), with few exceptions:

Phallus. The copulatory organ itself.

Basiphallus. The proximal sclerite, in Phoridae ring-shaped, that connects posteriorly to the distiphallus and ventrally to the hypandrium by the phallapodeme. Sometimes is projected posteriorly at dorsum.

Phallapodeme. Connection between the hypandrium and the venter of the basiphallus.

Distiphallus. All the rest of the copulatory organ. Brown (1987a, b) used the term referring to only part of what Emden & Hennig called distiphallus. Herein the distiphallus is used in Emden & Hennig’s sense, to the nonbasiphallus and non-phallapodeme parts of the phallus. The following terms correspond to parts of the distiphallus.

Right arm. Generally a large sclerotized structure adjacent to the basiphallus that sometimes turns ventrally and reaches the left lateral side. Can be connected to the epiphallus in its right and left part.

Epiphallus. Highly variable plate that generally extends under the core plate and sometimes bears scales or spines. Can connect to the right arm in both sides of the phallus.

Core plate. This term is taken from Nakayama (2007) to substitute the distiphallus in Brown’s terminology. It is a median large plate, sometimes membranous, that extended posteriorly from the basiphallus.