REVISION OF THE GENUS XYLOMOIA-STAUDINGER (LEPIDOPTERA, NOCTUIDAE), WITH DESCRIPTIONS OF 2 NEW SPECIES

Seven species are included in the genus Xylomoia Staudinger, two of wh ich are new: X. retinax sp.n. from the Novosibirsk area, Western Siber ia, and from the Chelyabinsk area, southern Ural Mountains, and X. sta ngelmaieri sp.n. from Caorle, Venezia Giulia, on the Adriatic coast. A North American species, Chortodes didonea (Smith) comb.n., is removed from the genus. According to a cladistic analysis, the genus Xylomoia comprises one plesiomorphic species group, the chagnoni group, and tw o apomorphic groups: the graminea and strix groups. The latter are exc lusively temperate Palaearctic. Xylomoia chagnoni (Barnes & McDunnough ) is the only Nearctic species of the genus, and the loosely related X . apameaoides (Hacker) was recently described from Turkey. In geograph ical isolation, these two species have retained many ancestral feature s. In the more central area, the common ancestor of the graminea and s trix groups has evolved into at least five species. The locality and r arity of the species of Xylomoia seemingly result from adaptation of t he species to moist habitats, the larvae probably bore inside grass st ems (the case of X. chagnoni). What are called lock-and-key mechanisms may lead to the use of non-independent character states in a cladisti c analysis; particularly in the case of homoplasy this kind of double- weighting may result in erroneous cladograms. In Xylomoia, deleting fe male lock-and-keys affected only the number of cladograms produced, wh ereas omitting the corresponding male characters had profound effects on the cladogram.