Prothyma (Symplecthyma) coerulea opacosericea Horn, 1929 comb. nov.

Prothyma lucidicollis opaco -sericea Horn 1909: 6 . Type locality: “SE Luzon: Mt. Isarog, Sorsogon ” .

Prothyma lucidicollis opaco -sericea: Horn 1934: 145, f. 4.

Prothyma (Genoprothyma) lucidicollis opacosericea: Wiesner 1980: 124 .

Prothyma (Symplecthyma) heteromallicollis opacosericea: Wiesner 1992: 58; Cabras, Cabigas & Wiesner: 193; Wiesner 2020: 139.

Prothyma (Symplecthyma) bella Dheurle & Colas 2018: 128, f. 1–4. syn. nov. Type locality: “S Luzon: Bicol, Camarines Sur ”. Wiesner 2020: 139; Johnson 2021: 50.

Type material: Lectotype (designed here) male: “ Sorsogon / Luzon [13.017473, 123.965785]”, “Baker”, “ Syntypus [red]”, “24178”, “Type / W. Horn”, “Coll. W. Horn / DEI Eberswalde”, “DEI Münchenberg / Col-14560 [green]”, “ssp/ opacoseri- / cea Horn [yellow]”, “ LECTOTYPE / Prothyma / ( Symplecthyma) / opacosericea W. Horn, 1929 / design. Anichtchenko & Wiesner 2023 [printed, red]” (SDEI). Paralectotypes: 1 male: “ Sorsogon / Luzon”, “Baker”, “ Syntypus [red]”, “Type / W. Horn”, “Coll. W. Horn / DEI Eberswalde”, “SDEI Coleoptera / # 301942”, “DEI Münchenberg / Col-14561 [green]”, “ PARALECTOTYPE / Prothyma / ( Symplecthyma) / opacosericea W. Horn, 1929 / design. Anichtchenko & Wiesner 2023 [printed, red]” (SDEI); 1 female: “ Philippinen / S Luzon / Mt Isarog [13.655399, 123.379272]”, “ Syntypus [red]”, “Type / W. Horn”, ‘SDEI Coleoptera / # 301941”, “ssp/ opacoseri- / cea Horn [yellow]”, “DEI Münchenberg / Col-14561 [green]”, “ PARALECTOTYPE / Prothyma / ( Symplecthyma) / opacosericea W. Horn, 1929 / design. Anichtchenko & Wiesner 2023 [printed, red]” (SDEI).

Other material examined: 1 male: “ Philippines / South Luzon, / Bicol Region / Coll. Dheurle ”, “ Camarines Sur / Province, Lagonoy / District, V-2018, I. Lumawig leg”, “local collector” [13.781836, 123.519917], “ HOLOTYPE / Prothyma (Symplecthyma) / bella Dheurle & Coles, 2018 [red label]” (CDc) ; 1 female: label idem, but “ PARATYPE / Prothyma (Symplecthyma) / bella Dheurle & Coles, 2018 [red label]” (GCc) . 2 females: “ Philippines, S Luzon, / Bicol, v/ vi.2018 / Lagonoy, Camarines Sur ” (PSc) ; 1 male: “Filippine-S Luzon / Camarines Sur / Lagonoy IV.2019 ” (RSc) ; 1 female: “Filippine-S Luzon / M. Mayon, Bicol / Tabacco IV.2022 [13.287213, 123.677548]” (RSc) .

Diagnosis. External characters as in nominative subspecies, except that subspecies from Luzon is characterized by head with only few external longitudinal striae on orbital plates straight and parallel; the rest of striae in frons, between eyes and vertex becoming strongly irregular and zigzag; rugae on neck and behind eyes strongly zigzag (Fig 4b, c).

Remarks. Shape of aedeagus and endophallus structure is very similar to nominative subspecies (Figs 4g, h). New combination is proposed here.

Distribution. The subspecies P. coerulea opacosericea Horn, 1929 comb. nov. is known from SE Luzon (Bicol region: Province Camarines Sur); Mt. Isarog, Sorsogon (Dheurle and Colas 2018: 128), Lagonoy.