Myrsidea franciscoloi (Conci, 1942)

Schneider, Marek, Kolencik, Stanislav, Literak, Ivan & Sychra, Oldrich, 2025, Redescriptions of three species in the louse genus Myrsidea (Insecta: Phthiraptera: Amblycera), Zootaxa 5653 (3), pp. 411-428 : 420-425

Myrsidea franciscoloi (Conci, 1942)

( Figs 14–19 , 29–32 )

Myrsidea franciscoloi Conci, 1942a: 287 ; figs 1–3.

Myrsidea franciscoloi Conci, 1942a ; Price et al. 2003: 129.

Type host: Cinclus cinclus aquaticus (Bechstein, 1797) ( Passeriformes , Cinclidae )—White-throated dipper. Type locality: Liguria, Italy.

Diagnosis

Both sexes of Myrsidea franciscoloi can be identified by the partially reduced hypopharyngeal sclerites ( Fig. 15 ), gula with 6–7 setae on each lateral side, and with 1–2 strong spine-like setae on each postero-lateral margin of the metanotum and tergites I–V ( Fig. 14 ). Such spine-like setae on those sclerites are quite unique within the genus Myrsidea . Males have an elongated genital sac sclerite with a triangular plate, distally tapered, with thin lateral arms and short, broad median sclerotization ( Figs 18–19 ). Females are further identified by non-enlarged tergites with straight posterior margins and wide median gaps on each row of tergal setae ( Fig. 14 ). Nevertheless, detailed descriptions of males and females of similar species are still necessary for their reliable differentiation.

Descriptions

Female (n = 23). As in Figs 14 , 30, 32 . Some data from the allotype female ( Fig. 30 ) are in square brackets. Hypopharyngeal sclerites partially reduced ( Fig. 15 ). Length of dhs 10, 0.07–0.09 [0.07]; dhs 11, 0.08–0.12 [0.10]; ratio dhs 10/11, 0.69–1.00 [0.70]. Ls5 0.05–0.08 long, latero-ventral fringe with 8–10 [8–9] setae. Gula with 6–7 [7] setae on each side. Pronotum with 6 [6] setae on posterior margin and 3–4 [3] short spiniform setae at each lateral corner. Prosternal plate with rounded anterior margin. First tibia with 3 [3] outer ventro-lateral and 4 [4] dorso-lateral setae. Mesonotum undivided. Metanotum not enlarged, with 6–8 marginal setae (the most posterolateral setae are not included); metasternal plate with 6–7 [6] setae; metapleurites with 2–3 [3] short strong spiniform setae. Femur III with 14–18 [16] setae in ventral setal brush.

Tergites not enlarged, all with straight posterior margin. Abdominal segments with well-defined median gap on each row of tergal setae. Tergal setae (postspiracular setae and short associated setae on tergites II–VIII are not included): I, 9–12; II, 8–12; III, 9–12; IV, 10–16; V, 8–14 [8]; VI, 7–12; VII, 6–10 [6]; VIII, 4 [4]. Short, strong, spine-like setae associated to postspiracular setae on tergites II–V. In addition to these setae there is one seta of the same type on each side of tergites II–V and on metanotum and tergite I ( Fig. 14 ). Postspiracular setae very long on II, IV and VIII (0.35–0.46) [0.37–0.40]; long on I and VII (0.20–0.35) [0.23–0.30]; and short on III, V and VI (0.10– 0.18) [0.12–0.14]. Inner posterior seta of last tergum not longer than anal fringe setae with length 0.03–0.06 [0.05]; length of short lateral marginal seta of last segment, 0.04–0.05. Pleurites without anterior setae, but with short spine-like setae on their posterior margins, as follows: I, 4–7 [5]; II, 6–9 [7]; III, 6–9 [7–8]; IV, 5–9 [7–8]; V, 6–8 [6–7]; VI, 5–7 [6]; VII, 4–6 [5]; VIII, 3 [3]; also with slender and longer setae on IV, 1–2; V, 1–3 [1–2]; VI, 1–2 [1]; VII, 1–2 [1–2]; pleurite VIII with inner setae (0.03–0.06) [0.06] as long as outer (0.03–0.05) [0.05]. Anterior margin of sternal plate II with a medial notch. Sternal setae: I, 0 [0]; II, 4–5 [4] in each aster ( Fig. 16 ), aster setae length: s1, 0.05–0.07; s2, 0.04–0.07; s3, 0.04–0.06; s4, 0.03–0.05; s5, 0.03–0.05; with 10–15 marginal setae between asters, 3–6 medioanterior; III, 21–30; IV, 26–37; V, 30–35; VI, 25–34 [29]; VII, 13–16 [16]; VIII–IX, 8–12 [7]; and 10–17 [11] setae on serrated vulval margin; sternites III–VII without medioanterior setae. Anal fringe formed by 28–43 [37] dorsal and 30–37 [32] ventral setae.

Dimensions: TW, 0.46–0.53 [0.46]; POW, 0.36–0.38 [0.36]; HL, 0.27–0.32 [0.28]; PW, 0.29–0.34 [0.30]; MW, 0.42–0.48 [0.44]; AWIV, 0.56–0.67 [0.58]; ANW, 0.20–0.25 [0.23]; TL, 1.36–1.62 [1.38].

Male (n = 13). As in Figs 17 , 29 . Some data from the holotype male ( Fig. 29 ) are in square brackets. Hypopharyngeal sclerites partially reduced ( Fig. 15 ). Length of dhs 10, 0.06–0.08 [0.08]; dhs 11, 0.08–0.12 [0.09]; ratio dhs 10/11, 0.60–0.89 [0.89]. Ls5 0.06–0.08 [0.07] long, latero-ventral fringe with 8–9 [7–8] setae. Gula with 6–7 setae on each side. Pronotum with 6 [6] setae on posterior margin and 3 [3] short spiniform setae on each lateral corner. Prosternal plate with rounded anterior margin. First tibia with 3 [3] outer ventro-lateral and 4 [4] dorso-lateral setae. Mesonotum undivided. Metanotum not enlarged with 4–6 [4] marginal setae (the most posterolateral setae are not included); metasternal plate with 6 setae; metapleurites with 2–3 (1 in one case on one side) [2] short spiniform strong setae. Femur III with 10–12 [11] setae in ventral setal brush.

Abdominal segments with a wide median gap in each row of tergal setae. Tergal setae (postspiracular setae and short associated setae on tergites II–VIII are not included): I, 4–8 [7]; II, 7–13 [8]; III, 7–12 [10]; IV, 8–12 [8]; V, 6–12 [9]; VI, 5–12 [7]; VII, 4–8 [4]; VIII, 3–4 [3]. Postspiracular setae very long on II, IV and VIII (0.32–0.44) [0.35–0.46]; long on I and VII (0.22–0.35) [0.26–0.29]; and short on III, V and VI (0.05–0.17) [0.06–0.14]. Length of inner posterior seta of last tergum, 0.04–0.09 [0.04]; short lateral marginal seta of last segment, 0.01–0.03 [0.02]. Pleurites without anterior setae, but with short spine-like setae on their posterior margins, as follows: I, 3–4 [5]; II, 5–6 [6]; III, 5–6 [6–7]; IV, 5–6 [6]; V, 4–5 [5–6]; VI, 2–4 [5]; VII, 2–4 [4–3]; VIII, 2–3 [3], and with slender and longer setae as follows: IV, 1 [1]; V, 1–2 [1–2]; VI, 1–2 [1–2]; VII, 2–3; pleurite VIII with inner setae (0.04–0.05) [0.04] twice as long as outer (0.02) [0.02–0.03]. Anterior margin of sternal plate II with a medial notch. Sternal setae: I, 0 [0]; II, 4–5 [4–5] in each aster, aster setae length: s1, 0.06–0.07; s2, 0.04–0.06; s3, 0.04–0.05; s4, 0.03– 0.04; s5, 0.03–0.04; with 9–12 [9] marginal setae between asters, 3–6 medioanterior; III, 20–28 [20]; IV, 23–29 [23]; V, 23–31 [26]; VI, 18–27 [22]; VII, 12–15 [13]; VIII, 2–4 [4]; remainder of plate, 6–7 [6]; and with 5–7 [6] setae posteriorly; sternites III–VII with medioanterior setae: IV, 2–3 [3]; V, 6–7 [7]; VI, 2–5 [2]. With 8–9 [8] internal anal setae. Genital sac sclerite as in Figs 18–19 , elongated with a broad, flattened triangular plate with distal tapering. Lateral arms are thin, almost invisible in some specimens. The median sclerotization is short and broad. The distal margin with slight apical indentation (slightly indented apex).

Dimensions: TW, 0.39–0.45 [0.41]; POW, 0.32–0.37 [0.33]; HL, 0.24–0.30 [0.27]; PW, 0.25–0.30 [0.26]; MW, 0.34–0.38 [0.34]; AWIV, 0.45–0.50 [0.45]; GW, 0.13–0.16 [0.15]; GL, 0.37–0.42 [0.45]; ParL, 0.08–0.10 [0.10]; GSL, 0.10–0.11 [0.10]; TL, 1.08–1.33 [1.12].

Material examined

Figures

FIGURES 14–19. Myrsidea franciscoloi: 14, dorso-ventral views of female. 15, hypopharynx. 16, female metasternal plate and sternites I–II. 17, dorso-ventral views of male abdomen, 18–19, male genital sac sclerites.

FIGURES 29–32. Myrsidea franciscoloi, habitus: 29, holotype male. 30, allotype female. 31, slides with type specimens. 32, female from Cinclus pallasii.