Guimaraesiella (Guimaraesiella) aedon, Gustafsson & Bush, 2025

Guimaraesiella (Guimaraesiella) aedon sp. nov.

( Figs 2–3 View FIGURES 1–2 View FIGURE 3 , 5 View FIGURES 4–5 , 9–12 View FIGURES 6–12 )

Type host: Nesospiza questi Lowe, 1923 — Nightingale Island finch.

Type locality: Nightingale Island , Tristan da Cunha Archipelago, South Atlantic.

Diagnosis. See under G. inaccessibilis , above.

Description

Both sexes. Head flat-dome shaped ( Fig. 5 View FIGURES 4–5 ), frons slightly flattened, lateral margins of preantennal area convex. Dorsal preantennal suture reaches dsms but does not reach ads or lateral margins of head. Head chaetotaxy as in Fig. 5 View FIGURES 4–5 . Thoracic and abdominal segments as in Figs 2–3 View FIGURES 1–2 View FIGURE 3 .

Male. Thoracic and abdominal chaetotaxy as in Fig. 2 View FIGURES 1–2 . Male genitalia as in Figs 9–11 View FIGURES 6–12 . Basal apodeme widening slightly anteriorly ( Fig. 9 View FIGURES 6–12 ). Proximal mesosome shorter than wide ( Fig. 10 View FIGURES 6–12 ). Mesosomal lobes with near-parallel lateral margins in proximal end, converging distally; small ridge near lateral margins; 2 ames sensilla on each side near ridge; 1 pmes sensillum and 2 pmes microsetae on each side lateral to gonopore. Gonopore wide proximally, narrowly open distally; wide rugose area follows proximal margin of gonopore, reaching lateral margins of mesosome. Parameral heads large, irregular ( Fig. 11 View FIGURES 6–12 ). Parameral blades short, slender; pst1 sensilla, near median margin; pst2 microseta, central. Measurements (n = 2): TL = 1.22–1.25; HL = 0.34; HW = 0.31–0.32; PRW = 0.19; PTW = 0.27–0.29; AW = 0.36–0.37.

Female. Thoracic and abdominal chaetotaxy as in Fig. 3 View FIGURE 3 . Subgenital plate broadly connected to partial cross-piece ( Fig. 12 View FIGURES 6–12 ). Vulval margin gently rounded ( Fig. 12 View FIGURES 6–12 ), with 2–3 long, slender vms on each side, and 3–5 short, thorn-like vss on each side; 5 long, slender vos on each side; distal 1 vos median to vss. Measurements (n = 2, except PTW, where n = 1): TL = 1.59–1.62; HL = 0.37; HW = 0.35–0.36; PRW = 0.22–0.24; PTW = 0.32; AW = 0.42–0.47.

Etymology: The specific name is derived from Greek “ aëdon ” for “nightingale”, referring to the type locality as well as the common name of the type host.

Type material. Ex Nesospiza questi : Holotype ♂, Nightingale Island , Tristan da Cunha Archipelago, South Atlantic, Oct./ Nov. 1988, Peter G. Ryan, N2/3 ( NHML). Paratypes: 1♂, 2♀, same data as holotype ( NHML) .