Halyomorpha halys fixed as the type species of the genus Halyomorpha (Hemiptera: Heteroptera: Pentatomidae)

Abstract: The genus Halyomorpha Mayr, 1864 (Hemiptera: Heteroptera: Pentatomidae: Pentatominae: Cappaeini) was established based on a single species, Halys timorensis Westwood, 1837 (currently a junior subjective synonym of Halyomorpha picus (Fabricius, 1794)). The examination of the voucher specimens identified as Halyomorpha timorensis by Mayr, a syntype of Halys timorensis, and syntypes of Pentatoma halys Stål, 1855 revealed that: i) Halyomorpha timorensis (Westwood), stat. restit., must be reinstated as a valid species, and not considered as a junior subjective synonym of H. picus; ii) Mayr’s specimens belong to two different species, Halyomorpha halys (Stål) and H. picus. The problem of double misidentification of the type species of Halyomorpha is resolved by action of the first revising author(s) according to the Article 70.3 of the ICZN (1999): we fix here Pentatoma halys Stål, 1855 (= Halys timorensis sensu Mayr, nec Westwood) as the type species of Halyomorpha Mayr, 1864. A list of 36 valid species currently placed in Halyomorpha and their synonyms is compiled. We also issue a warning concerning the use of the citizen science approach for monitoring H. halys in Southeast Asia (which may also apply to other taxa): It is necessary to keep in mind that H. halys belongs to a group of habitually similar species (distributed from Pakistan and southern China to Indonesia and the Philippines) which cannot be identified with certainty without examination of their male genitalia; records merely based on observations or habitus photographs cannot be accepted as reliable.

Key words: Hemiptera, Heteroptera, Pentatomomorpha, Pentatomidae, brown marmorated stink bug, action of first reviser, nomenclature, taxonomy, type species fixation, China, Timor, Oriental Region, Palearctic Region