Taxonomy and Phylogeny of the Aphid Genus Nippolachnus Matsumura, 1917, with Synonymy of the Mysterious Neonippolachnus Shinji, 1924 (Hemiptera: Aphididae: Lachninae)

Abstract

Nippolachnus Matsumura, 1917 is a small aphid genus from the tribe Tuberolachnini (Hemiptera: Lachninae) occurring in Southeast Asia. Species from this genus are quite characteristic and stand out among lachnids for their morphology and ecological associations. We have performed a revision and phylogenetic analyses to elucidate the relationships within Nippolachnus and other representatives of Tuberolachnini. Here, the taxonomy of the genus is revised based on morphological data to include seven species, three of them newly described: Nippolachnus chakrabartii sp. nov. from India, Nippolachnus sinensis sp. nov. from China, and Nippolachnus malayaensis sp. nov. from Indonesia. Nippolachnus appear to be non monophyletic genus and a new genus, Indolachnus gen. nov., is described to accommodate Nippolachnus himalayensis (van der Goot, 1917) as Indolachnus himalayensis (van der Goot, 1917) comb. nov. The new genus is a sister group to the remaining Nippolachnus species, which created a monophyletic clade. Neonippolachnus Shinji, 1924 syn. nov. is recognised as a synonym of Nippolachnus, and Neonippolachnus betulae Shinji, 1924 syn. nov. as a synonym of Nippolachnus micromeli Shinji, 1924. For the first time, a scanning electron microscopy study of the sexual generation of N. piri Matsumura, 1917 has been performed. Apterous and alate viviparous females of N. bengalensis Basu and Hille Ris Lambers, 1968, N. piri, and N. micromeli, and alate viviparous females of N. xitianmushanus Zhang and Zhong, 1982 are re-described and illustrated, as well as apterous and alate viviparous females of I. himalayensis comb. nov. Hitherto unknown morphs of N. micromeli, N. piri, and N. xitianmushanus are described. A lectotype and paralectotypes of N. xitianmushanus are designated herein. Notes on distribution and host plants are given, and keys to apterous and alate viviparous females of the genera Nippolachnus and Indolachnus are also provided.