New species and additional data on the chewing louse genus Myrsidea (Phthiraptera: Menoponidae) from wild Neotropical Passeriformes (Aves) Author Kolencik, Stanislav Author Sychra, Oldrich Author Papousek, Ivo Author Kuabara, Kamila M. D. Author Valim, Michel P. Author Literak, Ivan text Zootaxa 2018 4418 5 401 431 journal article 30109 10.11646/zootaxa.4418.5.1 fe001114-35af-46d5-bab4-4ab21689cdc6 1175-5326 1244956 04FEA195-71DA-4C7E-A62B-A658CFCF6B0C Myrsidea sp. 1 Material examined. Ex Taraba major (Vieillot, 1816) —great antshrike: 1♀ , Los Tres Gigantes Biological Station in the Paraguayan Pantanal , Paraguay ( 20°04'S , 50°09'W ), 7 September 2012 , I. Literak ( MMBC ). Remarks. This is the first record of a chewing louse from Taraba major . Our female is close to Myrsidea dacostai Price, Johnson & Dalgleish, 2008 from Thamnophilus doliatus (Linnaeus, 1764) , although it is considerably larger than specimens from the type host in almost all dimensions. This size discrepancy could be the result of a correlation with the size differences between the two hosts: Taraba major with length 19–20cm and weight 50–70g against Thamnophilus doliatus with length 15–16cm and weight 24–30g (see Zimmer & Isler 2003 ). Such correlation of host and louse size within a given louse genus is known as Harrison’s Rule (Price et al. 2003). Furthermore, both Taraba major and Thamnophilus doliatus have almost the same geographical distribution ( Clements et al. 2017 ). More data are necessary to test if these differences are due to intraspecific variation or if our female represents another, distinct, species. Our specimen differs from the original description of M. dacostai by setal counts and dimensions, as follows [data from Price et al. (2008b) are in parentheses]: Female (n = 1). Metanotum with 7 (5–6) marginal setae. Tergal setae: I, 15 (12–14); III, 17 (11–14). Sternal setae: II, 11 (14–16) marginal setae between asters, 3 (8–9) medioanterior setae. Anal fringe formed by 51 (44–50) dorsal and 40 (45–47) ventral setae. Dimensions: TW, 0.53 (0.49–0.50); HL, 0.37 (0.33–0.34); MW, 0.52 (0.48– 0.51); TL, 1.75 (1.58–1.66).