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 : 420-426

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

Ex Cinclus cinclus aquaticus (Bechstein, 1797)

Holotype ♂, ITALY, Liguria, date unknown, Conci’s Collection (skin CE26618, MSNG 545a ) . Allotype ♀, same locality as the holotype, 19 Sep. 1871 (Conci’s Collection, MSNG 276 ) . Paratypes 1♀, 2♂♂, same data as the holotype (Conci’s Collection, MSNG 545b & 545c ) ; 1♂ same data as the holotype ( NHML UK010661924 ) .

Non-types

Ex Cinclus cinclus aquaticus (Bechstein, 1797)

SLOVENIA: 7♀♀, 4 ♂♂, Polhov Gradec , 7 Dec. 1964 (Brelih’s Collection, PMSL) .

Ex Cinclus cinclus leucogaster (Bonaparte, 1850)

RUSSIA: 3♀♀, 1♂, Krasnojarskiy kr., Usinskiy tr. st., Kulumys, 6 Jun. 1940 (Blagoveshtchensky’s Collection, ZISP) ; 11♀♀, 6♂♂, Naryn us., 27 Feb. 1913, Sharkrotma 7000 fut. (Blagoveshtchensky’s Collection, ZISP) .

Ex Cinclus cinclus ( Linnaeus, 1758)

CZECH REPUBLIC: 5♀♀, 2♂♂, Kouty nad Desnou , 7 Aug. 1949 (Balát’s Collection, MMBC 422 ); 1♀, same data ( NHML UK010661925 ); 2♂♂, same data (B.M. 1951-325— NHML UK010661922-23 ) . MONTENEGRO: 1♂, Durmitor , 26 Jun. 1958 (Brelih’s Collection, USNM 465 ) .

Ex Cinclus pallasii (Temminck, 1820)

KOREA: 2♀♀, Kwang-Nung, Kyunggi , 11 Dec. 1964, H.E. McClure ( USNM SE-1585 ); 1♀, same data (B.M. 1965-555— NHML UK010661927 ) . Note: All 3♀♀ identified by T. Clay.

Remarks

The original description of Myrsidea franciscoloi does not include the minimum of 20 characters which should be given in a description of a Myrsidea species, according to Clay (1966). Myrsidea franciscoloi is the only Myrsidea species known from the host family Cinclidae . It has been recorded from Cinclus cinclus aquaticus in central and southern Europe: Bulgaria ( Ilieva 2009), Czech Republic, Slovakia ( Balát 1956, 1977), Germany ( Spitznagel 1985), Italy ( Conci 1942a), and United Kingdom ( Fowler & Hodson 1991). In addition, Doyle et al. (2005) reported M. franciscoloi from C. cinclus hibernicus Hartert, 1910 in Ireland. In this paper, we add records from Montenegro and Slovenia, and record M. franciscoloi from a new host, C. cinclus leucogaster , from the mountainous areas of central Asia ( Gill et al. 2024). Price et al. (2003: 129, 337) listed Cinclus pallasii as a valid host of M. franciscoloi without a reference, but this host-louse association was recorded in the review by Kolencik et al. (2024: Appendix 1) for two females from Korea. We have examined the same two females and confirm their identity as M. franciscoloi . It is possible that Price et al. (2003) included unpublished data from slide labels of lice deposited at the USNM.

Kolencik et al. (2024: 45) established the franciscoloi morphotype-group for species with a relatively common type of male genital sac sclerite and named it according to the first-described species of the group. The male genital sac sclerite of this morphotype-group is present in 30 species of Myrsidea parasitizing birds from nine passerine families and hummingbirds ( Kolencik et al. 2024: Table S3). However, species of the franciscoloi morphotype-group do not form monophyletic groups ( Kolencik et al. 2024). A reliable character to distinguish M. franciscoloi from other Myrsidea species is the presence of 1–2 strong spine-like setae on the postero-lateral margin of the metanotum and tergites I–V. This character is not common among Myrsidea species. In addition to M. franciscoloi, Kolencik et al. (2024: 33) reported it in Myrsidea singularis Tandan, 1972 (host family Leiothrichidae ), and Myrsidea victoriae Soto-Madrid & Sychra [in Soto-Madrid et al.], 2020 (host family Pellorneidae ). However, these two latter species differ in the type of male genital sac sclerite, and they belong to two different morphotype-groups: singularis and monilegeri, respectively ( Kolencik et al. 2024: 41, 42). Further research on both morphological and genetic data of all species placed in the franciscoloi morphotype-group is necessary to assess whether M. franciscoloi represents a separate evolutionary lineage associated with the host family Cinclidae only. Considering the significant phylogenetic influence of host families on the Myrsidea phylogeny ( Kolencik et al. 2022), incorporating genetic data is crucial for better understanding and accurate classification of the morphotype-groups and their relationship to the host families.

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.