On the morphology and taxonomy of the genera Halys and Neohalys (Heteroptera: Pentatomidae: Halyini)

Abstract

The male and female terminalia of Halys sulcatus (Thunberg, 1783) and H. magnus Chopra, 1974, nom. resurr. are redescribed in detail, including the completely inflated aedeagi. The distribution of these taxa is analysed. It is shown that H. sulcatus is reliably recorded only from the southern regions of India and H. magnus, only from the northern regions; numerous published records of “H. dentatus” from the central regions of India cannot be reliably attributed to either of these taxa. It is shown that almost all characters of the terminalia previously used to distinguish between H. sulcatus and H. magnus are highly variable and do not have a hiatus in their variability. Furthermore, the specimens were examined which exhibited an intermediate type of paramere between those in the two taxa. The material examined (which is not very extensive) revealed only one character that can consistently differentiate between northern and southern populations: the shape of armament on the anterior margin of parameral hypophysis (i.e., the position of a denticle and the presence or absence of a carina proximal to its base). However, a lack of correlation between these characters and with other, even less significant characters, as well as published evidence of the variability of the paramere, raise doubts about whether H. sulcatus and H. magnus are distinct species. Hypotheses about the status of these taxa are considered. It is shown that the name H. sulcatus was applied to the taxon described as H. magnus, based on a variable character of the female terminalia, which has no diagnostic value in this case. Additionally, the type locality of H. sulcatus is in the southern regions of India, where no reliably identified specimens of H. magnus have been found so far. Therefore, in this article H. sulcatus is recognised as a senior synonym of H. serriger Westwood, 1837, syn. resurr., and the name H. magnus Chopra, 1974, nom. resurr., is resurrected to the taxon distributed in the north. In addition, a detailed redescription of the female terminalia of Halys shaista Ghauri, 1988 and the male and female terminalia of Neohalys serricollis (Westwood, 1837) is provided. A new species, Halys brocchus sp. nov. is described, distinguished from all congeners primarily by a unique character of its pygophore. An updated identification key for species of the genus Halys Fabricius, 1803 is given. The name H. hyderabadiensis Memon, Parveen, Ahmad et Shah, 2017, syn. nov. is recognised as a junior synonym of H. magnus. Neohalys Azim, 2002, syn. nov., is recognised as a junior subjective synonym and a junior homonym of Neohalys Ahmad et Perveen, 1982. The names Neohalys acuticornis Ahmad et Perveen, 1982, syn. nov., N. longirostratus Ahmad et Perveen, 1982, syn. nov., and N. minirostratus Ahmad et Perveen, 1982, syn. nov. are placed in synonymy with N. serricollis.