Plyomydas Wilcox and Papavero, 1971

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), Revista Brasileira de Entomologia 61 (2), pp. 192-202 : 194

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.

Figures

Figs. 1–6. Photographs of male and female Plyomydas adelphe sp. nov.: (1) M* holotype (USNMENT01242234), dorsal (Morphbank #860756); (2) same, lateral (#860758); (3) same, head anterior (#860760); (4) F* paratype (AAM-004053), head anterior (#860784); (5) same, dorsal (#860780); (6) same, lateral (#860782). Scale line= 5 mm.

Figs. 15–20. Photographs of male and female Plyomydas phalaros sp.nov.: (15) M* holotype (AAM-005629),dorsal (Morphbank #860834); (16) same, lateral (#860836); (17) same, head anterior (#860838); (18) F* paratype (MZSP MZ003846), head anterior (#860752); (19) same, dorsal (#860524); (20) same, lateral (#860750). Scale line= 5 mm.

Figs.12–14. Photographsof male Plyomydas peruviensis (AAM-003731):(12) dorsal (Morphbank #860772); (13) same,lateral (#860774); (14) same,headanterior (#860776). Scale line= 5 mm.

Figs. 28–33. Photographs of male and female Messiasia notospila (Argentina: Entre Rios: Pronunciamiento, 32◦20Ɩ45ƖƖ S 058◦26Ɩ40ƖƖ W, 1970-03-00, Bolle, S.): (28) M* (CNCDiptera198880),dorsal (Morphbank #860859); (29) same,lateral (#860861); (30) same,head anterior(#860863); (31) F* (CNCDiptera198880),headanterior (#860870); (32) same, dorsal (#860866); (33) same, lateral (#860868). Scale line =5 mm.

Figs. 7–11. Male and female terminalia of Plyomydas adelphe sp. nov.: (1) M* paratype (MZSP-MZ003844), lateral (posterior gonocoxal processes highlighted in grey); (2) same, dorsal; (3) same, ventral; (4) F* paratype (AAM-004053), dorsal; (5) same, ventral. Scale line= 1 mm, setation omitted.Figshare DOI 10.6084/m9.figshare.4490462.

Figs. 21–26. Male terminalia of Plyomydas species: (21) Plyomydas peruviensis (AAM-003729), lateral; (22) same, dorsal; (23) same, ventral; (24) Plyomydas phalaros sp. nov. paratype (CASENT8380022), lateral; (25) same, dorsal; (26) same, ventral. Scale line =1 mm, setation omitted. Figshare DOI 10.6084/m9.figshare.4490474.