Plyomydas Wilcox and Papavero 1971
Creators: name: Castillo, Stephanie
name: Dikow, Torsten
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Mydidae
Plyomydas

description: Plyomydas Wilcox and Papavero, 1971
ZooBank 43AF4DE6-F7DE-4F35-801F-BF4248D531BB
Plazi TreatmentBank 43AF4DE6-F7DE-4F35-801F-BF4248D531BB
Plyomydas Wilcox and Papavero, 1971: 106.
Type-species: Plyomydas peruviensis Wilcox and Papavero, 1971, by original designation.
Diagnosis:The genus is distinguished from other Mydinae by the absence of a ventral metathoracic tibial keel (Figs. 2 and 20), only slightly enlarged metathoracic femora (Figs. 2 and 20), and a partly pubescent scutum (either stripes Fig. 12 or spots Fig. 19). Messiasia notospila (Wiedemann, 1828) (see Figs. 28–33) is somewhat similar to Plyomydas because it exhibits a weakly developed tibial keel and a grey pubescence pattern on the scutum, but can be separated from Plyomydas based on the more expanded metathoracic femur and male terminalia. The distinct ventro-posterior gonocoxal process is much more developed in Plyomydas than it is in Messiasia and the two other posterior gonocoxal processes (see Fig. 7) are unique to Plyomydas within Mydinae (J. Calhau, pers. comm.). See also Discussion for transfer of Plyomydas to Mydinae: Messiasiini.
Description: F* abdomen and genitalia (Figs. 10 and 11): densely arranged anteriorly directed setae absent on posterior T and S; T8 with broad anterior rectangular apodeme; T9 simple, rectangular; T9 + 10 entirely fused, T10 formed by single sclerite, acanthophorite spines absent; 3 spermathecae, all equally large, formed by ±expanded weakly sclerotized ducts; individual spermathecal duct short; S9 (furca) formed by 1 sclerite, inverted U-shaped (joined anteriorly, separated posteriorly), anterior furcal apodeme absent, lateral furcal apodeme present, median furcal bridge absent.
M* abdomen and terminalia (Figs. 7–9, 21–26): T1–7 welldeveloped, entirely sclerotized, T8 postero-medially weakly sclerotized, with anterior transverse sclerotized bridge connecting lateral sclerites; T7–8 anteriorly with 2 lateral apodemes; S6 regular, without any special setation postero-medially; S8 simple plate, entire (undivided) ventro-medially, with horn-like antero-lateral processes, not fused to T8 dorso-laterally; epandrium formed by two sclerites, separated medially and only joining anteriorly, distally in dorsal view pointed postero-laterally; subepandrial sclerite without lateral or median protuberances; hypandrium concave, cup-shaped, entirely sclerotized ventrally, entirely fused with gonocoxite, forming a gonocoxite-hypandrial complex, supra-hypandrial sclerite absent; gonocoxite simple, short, hooklike, without median or lateral protuberance, gonocoxal apodeme present, short (at most slightly extending hypopygium anteriorly); 1 functional phallic prong, short and wide, phallic epimere present, distally simple, evenly rounded; lateral ejaculatory process absent; ejaculatory apodeme formed by single dorso-ventrally oriented plate; ventro-median margin of parameral sheath heavily sclerotized (appearing entirely closed); parameral sheath long, sperm sac entirely covered; sperm sac appearing ± heavily sclerotized.
description: Published as part of Castillo, Stephanie & Dikow, Torsten, 2017, Taxonomic revision of Plyomydas Wilcox & Papavero, 1971 with the description of two new species and its transfer to Mydinae (Insecta: Diptera: Mydidae), pp. 192-202 in Revista Brasileira de Entomologia 61 (2) on page 194, DOI: 10.1016/j.rbe.2017.03.002, http://zenodo.org/record/10073509