Revision of the genus Amblytylus and an attempt to improve our understanding of the genera Amblytylus and Megalocoleus (Heteroptera: Miridae: Phylinae)

Revision of the genus Amblytylus and an attempt to improve our understanding of the genera Amblytylus and Megalocoleus (Heteroptera: Miridae: Phylinae). The twenty-two species currently placed in the Palaearctic genus Amblytylus Fieber are revised. The genus is redefined principally with reference to characters of the male genitalia. Ten species are retained in this genus: A. albidus (Hahn 1834), A. amoenus Wagner 1958, A. arnoldiorum Kerzhner 1977, A. brevicollis Fieber 1858, A. concolor Jakovlev 1877, A. crassicornis Wagner 1964, A. jani Fieber 1858, A. montanus Wagner 1974, A. nasutus (Kirschbaum 1856), and A. peitho Linnavuori 1997. In this revision, however, we regard A. amoenus as incertae sedis and A. jani as a nomen dubium. Two species are transferred to the genus Megalocoleus Reuter: Megalocoleus delicatus (Perris 1857) n. comb., Megalocoleus tarsalis (Reuter 1894) n. comb. Ten species are placed in synonymy; either with species of Amblytylus: A. similis Wagner 1971 n. syn. of A. albidus (Hahn 1834); A. gregarius Linnavuori 1961 n. syn. of A. brevicollis Fieber 1868; A. vittiger Reuter 1899 n. syn., A. longicornis Wagner 1953 n. syn., A. eckerleini Wagner 1964 n. syn. of A. concolor Jakovlev 1877; or with a species of Megalocoleus: A. erectus Wagner 1971 n. syn. of M. longirostris (Fieber 1861); A. glaucicollis Kerzhner 1977 n. syn. of M. exanguis (Herrich-Schaeffer 1835); A. macedonicus Wagner 1956 n. syn. of M. naso (Reuter 1879) n. comb.; A. luridus Hoberlandt 1961 n. syn. and A. scutellaris Horvath 1905 n. syn. of M. delicatus (Perris 1857) n. comb. Lectotypes are designated for four species (Lopus nasutus Kirshbaum, Amblytylus vanduzeei Blatchey, Amblytylus scutellaris Horvath, Capsus delicatus Perris 1857). A bilingual (French and English) identification key to the species of Amblytylus, based mainly on external characters, is presented. A revised key to the species of Megalocoleus is also given. The two genera Amblytylus and Megalocoleus are very similar in general appearance and remain difficult to define. The existence of two distinct groups of species seems to be indicated only by their host plants (the Poaceae in the case of Amblytylus, and Asteraceae in the case of Megalocoleus), and to a lesser extent by the vesica, with either two apical processes (Amblytylus) or only one (Megalocoleus).