Myrsidea quadrifasciata (Phthiraptera: Amblycera) – a unique host generalist among highly host-specific chewing lice

Abstract Ten species of the louse genus Myrsidea belonging to the “serini-species-group” have been reviewed. A redescription of Myrsidea quadrifasciata (Piaget, 1880), the earliest described and valid species of this species complex, is given and a neotype for this species is designated. Nine new junior synonymies of M. quadrifasciata are proposed and discussed. The new synonyms and their respective type hosts are: Myrsidea anoxanthi Price and Dalgleish, 2007 from Loxipasser anoxanthus (Gosse, 1847), Myrsidea argentina (Kellogg, 1906) from Spinus magellanicus (Vieillot, 1805), Myrsidea balati Macháček, 1977 from Passer montanus (Linnaeus, 1758), Myrsidea darwini Palma and Price, 2010 from Geospiza fuliginosa Gould, 1837, Myrsidea major (Piaget, 1880) from Plectrophenax nivalis (Linnaeus, 1758), Myrsidea serini (Séguy, 1944) from Serinus serinus (Linnaeus, 1766), Myrsidea queleae Tendeiro, 1964 from Quelea quelea lathami (Smith, A., 1836), Myrsidea textoris Klockenhoff, 1984 from Ploceus cucullatus cucullatus (Müller, 1776), and Myrsidea viduae Tendeiro, 1993 from Vidua macroura (Pallas, 1764). Intraspecific morphometric variability, relative genetic divergence (based on a 379 bp portion of the mitochondrial COI gene and a 347 bp portion of the nuclear EF-1α gene), geographical distribution, and host associations, including 8 new host records for these lice, are discussed. Taking into consideration these parameters we suggest that the only way to deal with these taxa is to follow concept of subspecies with the following taxa and their geographic distributon: Palearctic Region: M. q. quadrifasciata and M. q. serini, Neotropical Region: M. q. anoxanthi, M. q. argentina, M. q. darwini, Paleotropic Region: M. q. queleae, M. q. textoris and M. q. viduae.