Myrsidea flavida ( Piaget, 1880 )

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 : 417-420

Myrsidea flavida ( Piaget, 1880)

( Figs 7–13 , 25–28 )

Menopon flavidum Piaget, 1880: 438 , pl. XLII: fig. 5.

Myrsidea flavida ( Piaget, 1880) ; Price e t al. 2003: 129.

Type host: Eurylaimus ochromalus Raffles, 1822 ( Passeriformes , Eurylaimidae )—Black-and-yellow broadbill.

Type locality: Unknown.

Diagnosis

Myrsidea flavida is easily identified by its unique male genital sac sclerite—long and narrow with a poorly developed distal margin and short distal arms forming a small lateral hook ( Figs 9–13 ). Kolencik et al. (2024: 40) established the flavida morphotype-group for this species. Females are defined by the following combination of characters: metanotum slightly enlarged; tergite I enlarged with a deep mediocentral convexity; tergites II–IV modified by enlarged tergite I; abdominal segments I–III and VI–VIII with well-defined median gap on each row of tergal setae; segments IV–V with a continuous row of tergal setae ( Fig. 7 ).

Descriptions

Female (n = 2). As in Figs 7 , 27 . Hypopharyngeal sclerites fully developed ( Fig. 27 ). Length of dhs 10, 0.03– 0.04; dhs 11, 0.10–0.11; ratio dhs 10/11, 0.25–0.36. Ls5 0.06 long; latero-ventral fringe with 11 setae. Gula with 3–5 setae on each side. Pronotum with 6 setae on the posterior margin and 3 short spiniform setae on each lateral corner. Prosternal plate with rounded anterior margin. First tibia with 3 outer ventro-lateral and 3–4 dorso-lateral setae. Mesonotum undivided. Metanotum enlarged, with 6–9 marginal setae (the most posterolateral setae are not included); metasternal plate with 6 setae; metapleurites with 3 short strong spiniform setae. Femur III with 15–16 setae in ventral setal brush.

Tergites modified as follows: tergite I enlarged with deep mediocentral convexity; II strongly modified by enlarged tergite I, with straight mediocentral margin; III slightly modified by enlarged tergite I ( Fig. 7 ). Abdominal segments I–III and VI–VIII with well-defined median gap on each row of tergal setae; abdominal segments IV–V with a continuous row of tergal setae. Tergal setae (postspiracular setae and short associated setae on tergites II–VIII are not included): I, 5–8; II, 8–11; III, 10; IV, 14–22; V, 12–21; VI, 9–13; VII, 7–12; VIII, 3–4. Postspiracular setae very long on II, IV, VII and VIII (0.36–0.45); long on I (0.26); and short on III, V and VI (0.10–0.18). Inner posterior seta of last tergum not longer than anal fringe setae with length 0.02; length of short lateral marginal seta of last segment, 0.05–0.06. Pleural setae: I, 5–6; II, 9; III, 9–11; IV, 8–10; V, 8–9; VI, 6–7; VII, 5–6; VIII, 3. Pleurites without anterior setae; pleurites I–III with only short spine-like setae; pleurite IV with 2–3 long slender setae; V with 3–4; VI with 2; VII with 4; Pleurite VIII one with inner seta (0.05–0.07 long) and an outer seta (0.05–0.08) plus a very long median seta ( Fig. 7 ). Anterior margin of sternal plate II with a medial notch ( Fig. 8 ). Sternal setae: I, 0; II, 4 on each aster, aster setae length: s1, 0.07–0.09; s2, 0.05; s3, 0.04; s4, 0.03–0.04; with 16–18 marginal setae between asters, 6 medioanterior ( Fig. 8 ); sternite III, 20–24 setae; IV, 32–34; V, 34–36; VI, 28; VII, 13–15; VIII–IX, 8; and 9–10 setae on deeply serrated vulval margin. Sternites III–VII without medioanterior setae. Anal fringe formed by 32–36 dorsal and 30–31 ventral setae.

Dimensions: TW, 0.41–0.44; POW, 0.34–0.36; HL, 0.33; PW, 0.28–0.30; MW, 0.48–0.55; AWIV, 0.65–0.70; ANW, 0.21–0.26; TL, 1.63–1.70.

Male (n = 5). As in Figs 26, 28 . Some data from the lectotype male ( Figs 25–26 ) are in square brackets. Hypopharyngeal sclerites fully developed ( Fig. 28 ). Length of dhs 10, 0.02–0.03; dhs 11, 0.09–0.11; ratio dhs 10/11, 0.20–0.33. Ls5 0.06–0.07 long, latero-ventral fringe with 9–11 [9–10] setae. Gula with 4–5 [4–5] 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 [6] setae; metapleurites with 3 [3] short spiniform strong setae. Femur III with 13–16 [15–17] setae in ventral setal brush.

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, 7–8 [10]; II, 8–9 [10]; III, 6–8 [11]; IV, 6–9 [10]; V, 6–7 [7]; VI, 4–6 [7]; VII, 4–7 [7]; VIII, 4 [4]. Postspiracular setae very long on II, IV, VII and VIII (0.42–0.54); long on I (0.14–0.19; short on III, V and VI (0.10–0.13). Length of inner posterior seta of last tergum, 0.05–0.07; short lateral marginal seta of last segment, 0.02. Pleural setae: I, 3–5 [4]; II, 5–8 [6]; III, 6–8 [7]; IV, 5–7 [6]; V, 5–6 [6]; VI, 4–6 [5]; VII, 4–5 [4]; VIII, 3 [3]. All pleurites with only short spine-like setae, and without anterior setae. Pleurites IV, 1–2 [1]; V, 1–3 [2]; VI, 1–3 [2]; VII, 2–3 [2] with slender and longer setae. Pleurite VIII with inner setae (0.05–0.07) twice as long as outer (0.02–0.04). Anterior margin of sternal plate II with a medial notch. Sternal setae: I, 0 [0]; II, 3–4 [4] in each aster, aster setae length: s1, 0.08–0.09; s2, 0.05–0.06; s3, 0.04–0.05; s4, 0.04–0.04; with 15–18 [16] marginal setae between asters, 2–6 [6] medioanterior; III, 17–20 [19]; IV, 18–24 [26]; V, 26–28 [35]; VI, 18–30 [27]; VII, 14–16 [15]; VIII, 2–4 [4]; remainder of plate, 6–7 [6]; and with 4–6 [4] setae posteriorly; sternites III–VII without medioanterior setae. With 6–8 [8] internal anal setae. Genital sac sclerite long and narrow with poorly developed distal margin that can be easily distorted; distal arms (sensu Kolencik et al. 2024) short, forming a small lateral hook ( Figs 9–13 ).

Dimensions: TW, 0.38–0.41 [0.43]; POW, 0.31–0.33 [0.33]; HL, 0.29–0.30 [0.29]; PW, 0.26–0.29 [0.29]; MW, 0.29–0.38 [0.38]; AWIV, 0.46–0.50 [0.48]; GW, 0.13–0.15 [0.10]; GL, 0.38–0.43 [0.44]; ParL, 0.08–0.09 [0.08]; GSL, 0.07–0.09 [0.08]; TL, 1.33–1.37 [1.36].

Material examined

Ex Eurylaimus ochromalus Raffles, 1822 —Black-and-yellow broadbill

Lectotype ♂: locality and collection date unknown (Piaget’s Collection 813— NHML UK010711664 ).

Non-types

Ex Eurylaimus ochromalus Raffles, 1822 —Black-and-yellow broadbill

THAILAND: 1♂, 1♀ Phatthalung Muang Ban Na., Na Wong , 9 Sep. 1963, Wanit Songprakob leg. (Elbel’s Collection, PIPeR 7137–8 ) identified by R.D. Price; 1♀, 3 ♂♂, same locality, 9 Mar. 1963 ( USNM) .

Ex Eurylaimus sp.

1♀, locality and date unknown , (Eichler’s Collection, MFNB) .

Ex Motacilla alba

TAIWAN (FORMOSA): 1♀, 1♂, (as Myrsidea cf. dukhunensis ), Ping-tung Hsien , Fang Liao, 4 Apr. 1960, (Elbels’ Collection, PIPeR 10236 ); 1♀, 1♂, same data ( USNM). These four specimens are regarded as stragglers ( Kolencik et al. 2024: Appendix) .

Remarks

The original description of Myrsidea flavida provides only scarce morphometric data and poor-quality illustrations, hence our redescription supported by illustrations from both sexes. Myrsidea flavida is one of three known species of Myrsidea from hosts of the family Eurylaimidae ( Sychra et al. 2014; Chu et al. 2019; Kolencik et al. 2024). Myrsidea claytoni Hellenthal & Price, 2003 and M. palmai Hellenthal & Price, 2003 were originally described from bulbuls ( Pycnonotidae ): Pycnonotus eutilotus (Jardine & Selby, 1837) from Sarawak, and Alophoixus ochraceus (Moore, F, 1854) from Thailand, respectively ( Hellenthal & Price 2003). However, M. claytoni was subsequently recorded on Cymbirhynchus macrorhynchos (Gmelin, JF, 1788) ( Eurylaimidae ) in Vietnam by Sychra et al. (2014), and M. palmai was recorded on Serilophus lunatus (Gould, 1834) ( Eurylaimidae ) in China by Chu et al. (2019). These two species differ from M. flavida by the male genital sac sclerite (see above for detailed description of M. flavida ), which in M. claytoni and M. palmai have distal arms strongly curved laterally to form conspicuous hooklike projections, and lateral arms with deeply serrated lateral margins and proximal part continuing to a quite large subapical projection of an irregular shape (see Figs. 217–218 in Kolencik et al. 2024). Therefore, Kolencik et al. (2024: 38) placed the latter two species in the palmai morphotype-group.

Figures

FIGURES 7–13. Myrsidea flavida: 7, dorso-ventral views of female thorax and abdomen. 8, female metasternal plate and sternites I–II. 9–13, various views of the male genital sac sclerite.

FIGURES 25–28. Myrsidea flavida: 25, slide with lectotype. Habitus: 26, lectotype male. 27, female. 28, male.