Plagiodera CHEVRO- LAT, 1836

Eva Sprecher- Uebersax & Mauro Daccordi, 2016, Notes on the species of Plagiodera CHEVROLAT, 1836 of the Australian, Oceanic and Oriental regions, with a description of P. hiekei n. sp. (Coleoptera, Chrysomelidae), Entomologische Blätter und Coleoptera 112 (1), pp. 373-385 : 375-376

Notes on the biogeography of the Australian and Oceanic species of Plagiodera CHEVRO- LAT, 1836

Remarks. In the Oriental, Australian and Oceanic regions, the genus Plagiodera shows two distinct tracks, which can be dated: one in the Miocene and the other in the Pliocene-Pleistocene ( MATILE 1990) ( Fig. 62 ). As some species populate North India and Nepal (SPRECH- ER- UEBERSAX 2011), the temporal scale might be also old- er. Another hypothesis could be a more recent dispersal in North India and the Himalayan region from Southeast Asia. The diffusion of these species in the Pacific area might also have occurred in several successive waves. Thus, we agree with SANMARTIN & RONQUIST (2004).

Plagiodera of the Oriental region and the Indochinese and Malayan subregion. The species P. atmanama, P. cupreata, P. rufescens and P. yunnanica ( Figs 72, 73, 74, 75, 76) are known only in the strictly limited Indochinese subregion, while in the Malayan subregion the single peculiar species P. riparia is known, which is also widespread in Bali, Flores, Sulawesi (Celebes), Aru and West New Guinea and, to be confirmed, into the Northern Territory of Australia.

Plagiodera of the Oriental region and the Papuan and Polynesian subregions. In New Guinea, all groups of Plagiodera discussed in this study are present. P. riparia belongs to species group “A” to which P. riparia and P. hiekei n. sp. also belong. P. riparia is known from various localities in New Guinea: Adelbert Mts., Wanuma; north-east Kepilam (2600 m); Sorong, Salawatti; Biak Island; Kampong; NE Wum; Japen Island; Kontiunai; Iba; Wamena, Ibele river valley; Balien valley; Kainantu; Jayawijaya, Wamena. The species group “B” includes species known from Australia (P. lownei, P. nitidipennis, P. amplipennis) as well as from the Philippines (P. philippinensis, Figs 77, 78) and P. chapuisi from New Guinea Fly River, Woodlark (Murua), Noemandly I, Wakaiuna ( Figs 79, 80, 81, 82). P. cheni ( Fig. 83) belongs to species group “C” together with species that have colonized some Pacific archipelagos, such as P. violaceipennis in the Solomon Islands, Suva and Fiji, P. fulvicollis of the New Hebrides and Samoa with P. samoana.

Plagiodera of the Oriental region, subregion Philippines. In this subregion, there are only two species of group “A” (P. aerea and P. punctipennis) and a single one (P. philippinensis) from group “B”. In Sumbawa, J. ACHARD identified a single female specimen using an unpublished taxon name. This specimen is conserved in the collections of NMP and has been studied by one of the authors (M.D.) and might fit within the range of variation of the widespread P. riparia. P. philippinensis and P. punctipennis, belonging to two different groups, both have the same coloration of entirely Spectrum Orange.

Plagiodera of the Australian Region. Among the four species known for the Australian region and described as Pseudoparopsis BLACKBURN, 1899, three belong to group “B” (P. lownei, P. nitidipennis, P. amplipennis) and a single one, known from the Northern Territory, Mt. Bundey, 144 m, but not yet described, to group “A”. If this undescribed species is confirmed (a single female is in the collection MDC), it would be evidence of a population in the Australian region originating from the Malayan subregion. The other species known from a few localities in Oriental Australia and attributed to group “B” would indicate a population in the evergreen tropical forests proceeding from New Guinea via Cape York. The discovery of P. fulvicollis in New Caledonia needs confirmation. No Plagiodera are known from New Zealand.

Figures

Fig. 62. Plagiodera spp., distribution area of the studied species. The dotted area represents the track Pliocene-Pleistocene (L. MATILE 1990). □ GroupA:P.aerea(Philippines);P.riparia(Sulawesi,Bali,NewGuinea,Australia:N.Territory?);P.hiekei n.sp.(NewGuinea); P.punctipennis (Philippines). ● Group B: P. chapuisi (New Guinea); P. lownei (Australia); P. nitidipennis (Australia); P.amplipennis (Australia); P. philippinensis (Philippines). * Group C: P.cheni (New Guinea,Bismarck:New Ireland); P.violaceipennis(Solomon, Fiji,Tonga);P.fulvicollis (New Hebrides, New Caledonia?); P.samoana (Samoa). M = male; F = female. Notes:The data of Tonga (P.cheni group) is taken from the catalogue of C.A.M.REID: Chrysomelinae ofAustralia, New Guinea, New Zealand, Pacific Region and relevant S EAsian Taxa. 1993, unpublished manuscript kindly provided to one of the authors (M.D.).Probably P.violaceipennisandP.fulvicollisare synonyms andP.samoanais onlyasubspecies ofthis complex.For more precise findings we need deeper studies based on much more material.