Chewing lice of the genus Myrsidea (Phthiraptera: Menoponidae) from New World warblers (Passeriformes: Parulidae) from Costa Rica, with descriptions of four new species Author Kounek, Filip Author Sychra, Oldrich Author Capek, Miroslav Author Literak, Ivan text Zootaxa 2011 3137 56 63 journal article 45736 10.5281/zenodo.205057 33d95712-880e-4ad3-a42f-eb2fe3b3f09a 1175-5326 205057 Myrsidea basileuteri Kounek & Sychra sp. nov. ( Figs. 1–4 ) Type host: Basileuterus rufifrons (Swainson) —Rufous-capped warbler Female (n = 9) . Hypopharyngeal sclerites well developed ( Fig. 1 ). Length of head seta 10, 0.045–0.050; seta 11, 0.095–0.100; ratio10/11, 0.45–0.50. Gula with 4 setae on each side. Metasternal plate with 6–7 setae; metanotum not enlarged, with 8–10 marginal setae. Abdominal tergites not enlarged, with posterior margins almost straight, with median gap in each setal row ( Fig. 2 ), and setal numbers as follows: I, 9–12; II, 11–13; III, 10–14; IV, 9–11; V, 8–10; VI, 8; VII, 7–8; VIII, 8. Postspiracular setae: extremely long (0.43–0.50) on II, IV and VIII; very long (0.28–0.33) on I and VII; and conspicously shorter (0.14–0.18) on III, V and VI. Sternal setae: II, 4 in each aster, 13–15 marginal between asters, 4– 5 anterior; III, 17–20; IV, 25–27; V, 27–32; VI, 21–24; VII, 10–12; VIII–IX, 13–16 including 7–8 setae on deeply serrated vulval margin; without medioanterior sternal setae. Inner posterior seta of last tergum not longer than anal fringe setae with length 0.05–0.07; length of short lateral marginal seta of last tergum, 0.03–0.04. Dimensions: TW, 0.41; HL, 0.28–0.32; PW, 0.23–0.25; MW, 0.37–0.39; AW, 0.47–0.53; TL, 1.21–1.32; ANW, 0.17–0.18. Male (n = 3) . Length of head seta 10, 0.045–0.050; seta 11, 0.095–0.100; ratio10/11, 0.45–0.50. Gula with 4 setae on each side. Metasternal plate with 6 setae, metanotum with 6–8 marginal setae. Tergal setal counts: I, 7–10; II, 10–12; III, 10–13; IV, 8–10; V, 8–10; VI, 8; VII, 8; VIII, 7–8. Postspiracular setae: extremely long (0.40–0.42) on II, IV and VIII; very long (0.23–0.28) on I and VII; and conspicously shorter (0.13–0.20) on III, V and VI. Sternal setae: II, aster 2–4, 11 marginal between asters, 3 anterior ( Fig. 3 ); III, 12–14; IV, 20–22; V, 22–26; VI, 18–21; VII, 10; VIII, 7; without medioanterior sternal setae. Genital sac sclerite with slight apical indentation, distinct subapical lateral projection on each side and with dark medioposterior line ( Fig. 4 ). Dimensions: TW, 0.38–0.39; HL, 0.27–0.30; PW, 0.22–0.24; MW, 0.32–0.33; AW, 0.39–0.40; TL, 1.08–1.16; GW, 0.09–0.10; GSL, 0.07–0.08. Type material. Female holotype (O. Sychra CR171) ex Basileuterus rufifrons (Swainson) , COSTA RICA : Rincon de la Vieja Vieja National Park, Miravieja Lodge ( 10°43’N , 85°18’N ; elevation 600 m ), 19 August 2009 , Sychra and Literak leg. Paratypes : 1 female and 2 males (O. Sychra CR171–172), with same data as holotype ; 1 female and 1 male (O. Sychra CR173) ex Basileuterus rufifrons , COSTA RICA : Rincon de la Vieja National Park, Sector Santa Maria, Sendero del Padre ( 10°46’N , 85°18’N ; elevation 800 m ), 20 August 2009 . Deposited in INBio . Other specimens deposited in MZM. Remarks. This is the first record of chewing lice from Basileuterus rufifrons . Myrsidea basileuteri is characterized by the following characteristics: (1) well developed hypopharyngeal sclerites; (2) wide median gap in all rows of tergal setae; (3) metanotum not enlarged with almost straight posterior margin; (4) all abdominal tergites of female of essentially similar size each with straight posterior margin; (5) tergite VIII with not>8 setae; (6) male genital sac sclerite as in Fig. 4 . These characters place M. basileuteri close to M. ridulosa (see Palma & Price 2010 ). While the male of M. basileuteri is almost indistinguishable from that of M. ridulosa – it slightly differs by its smaller PW (0.22–0.24 vs. 0.25) and MW (0.32–0.33 vs. 0.36) and a small number of sternal setae, for example on sternite IV (20–22 vs. 24–26) and on V (22–26 vs. 29–30) – the female of M. basileuteri can be separated from that of M. ridulosa by the following combination of features: (1) metanotal margin with not>10 setae; (2) postspiracular setae on VII long, distinctly larger than those on V and VI, (3) smaller number of setae on tergites I–V. Etymology. The specific name derives from the generic name of the type host.