Five new species of Myrsidea Waterston (Phthiraptera: Menoponidae) from antshrikes and antbirds (Passeriformes: Thamnophilidae) Author Price, Roger D. Author Johnson, Kevin P. Author Dalgleish, Robert C. text Zootaxa 2008 1819 55 62 journal article 10.5281/zenodo.182969 a9ab8c8e-37c4-4887-a504-8e452803a87c 1175-5326 182969 Genus Myrsidea Waterston Myrsidea Waterston 1915 : 12 . Type species: Myrsidea victrix Waterston, 1915 , by original designation. A thorough characterization of this genus may be found in Clay (1966) . We provide here only the characters we have found to be pertinent to the delineation of the genus as it pertains to the thamnophilid lice. Head ( Fig. 1 ) evenly rounded anteriorly; lacking lateral slit or notch; with long inner and minute outer occipital seta on each side; each temple margin with 4 very long setae; without ventral sclerotized processes; gula with 4, less often 3 or 5, setae on each side with posterior seta heavier and longer than those anterior to it. Thorax ( Fig. 1 ) with pronotum lacking central setae; with 3 short setae at each lateral angle and 6 longer posterior marginal setae. Mesonotum well defined, with 2 minute medioanterior setae adjacent to postnotum and 2 minute setae at posterior margin. Metanotum not enlarged, without central setae, but with 6 short anterior setae around periphery and with very long seta at lateroposterior corner in addition to other marginal setae. Prosternal plate well developed, elongate, with 2 short anterior setae; metasternal plate prominent, diamond shaped; venter of femur III with setal brush. Abdomen ( Figs. 1, 2 ) having undivided tergites; without anterior setae except for a very small seta near lateroanterior corner on each side of tergite I (not included in setal count); tergal setal rows with pronounced gap in center of each row; sternite I small, without setae; sternite II enlarged, with aster of small number of heavy setae at each lateroposterior corner. Postspiracular setae very long on I (0.17–0.33), extremely long on II, IV, and VIII (at least 0.40), shorter on III, V, and VI (0.12–0.20), and usually at least 0.35 on VII. Pleurites without anterior setae. Female anus oval, without inner setae. Female subgenital plate of fused sternites VII– IX; setae given for VII represent those anteriorly located on region of segment VII, and those for VIII–IX are the remainder of the plate setae. Male subgenital plate of fused sternites VIII–IX; setae given for VIII represent those anteriorly located on region of segment VIII; the remainder of the plate setae are not quantified; genitalia of characteristic shape ( Fig. 4 ), with spinous sac having distinctively shaped associated sclerite ( Figs. 3, 5 ). Sexual dimorphism is limited to males having smaller dimensions, often sparser abdominal chaetotaxy, and differences associated with the posterior abdomen. Female and male abdominal tergites are essentially unmodified, with the pattern of postspiracular setal lengths similar for both sexes; female tergites II, III, and IV with at most only a very slight medioposterior convexity. The above-listed characters and those below for each of the two species groups will not be repeated in the species descriptions.