"This contribution to knowledge the wild silkmoths (Lepidoptera: Saturniidae) is dealing with the biodiversity of the taxa of the tribus Saturniini in the Malay Archipelago. Comparisons with the biodiversity of the wild silkmoths of the tribus Saturniini from mainland Asia (including the Andamans, Hainan and Taiwan) and Australia (including Tasmania) are provided. Because no autochthonous Saturniidae are known from New Zealand, the island is largely excluded here. An attempt is also made to clarify where the Saturniids in the Malay Archipelago originally came from and how they spread via the Malay Archipelago. As already noted in the previous contribution (Part I) on the biodiversity of the wild silkmoths of the tribus Attacini, taxa of the genera Aglia OCHSENHEIMER, 1810 (Agliinae) and Salassa MOORE, 1859 (Salassinae), Cachosaturnia NAUMANN, LÖFFLER & NÄSSIG, 2012, Neoris MOORE, 1862, Rhodinia STAUDINGER, 1892, Rinaca WALKER, 1855, Saturnia VON PAULA SCHRANK, 1802, Sinobirma BRYK, 1944, and Solus WATSON, 1913 (Saturniinae) are currently not distributed in the Malay Archipelago. There is also one Australian genus of the Saturniidae completely absent in the Malay Archipelago. This is Austrocaligula COCKERELL in Packard, 1914, while Opodiphthera WALLENGREN, 1858 is available in the Malay Archipelago with a single taxon only. The genus Pararhodia COCKERELL in Packard, 1914 and the venusta-group of the genus Neodiphthera FLETCHER in Fletcher & Nye, 1982 are restricted to the island of New Guinea which belongs geographically to the Australian Continent but is isolated now again after the rising of the sea level during the previous post glacial. The widespread sciron-group of Neodiphthera ranges from Buru I. (central Moluccas / Wallacea) to Guadalcanal (Solomon Archipel). A second species-group of Neodiphthera also occurs in Wallacea, this is the venusta-group. That means that three Papuan-Australian genera of the tribus Saturniini spread into the Wallacea from the Australian Continent (Australia and New Guinea), those are Opodiphthera, Syntherata, and Neodiphthera. The sciron-group of Neodiphthera is the most widely ranging Papuan-Australian species-group.
The Thai/Malay Peninsula not belongs to the Malay Archipelago geographically but is part of Sundaland, also called the Sundaic region. Sundaland is a biogeographical region of southeastern Asia corresponding to a landmass (Sunda Shelf) that was exposed during periods when sea levels were much lower throughout the last 2.6 million years (mya) – the “ice-ages”. MacKinnon, Hatta, Halim & Mangalir (1996) reported a sea level that was up to 200 m lower than today, other authors reported up to about 120-130 m for the previous glacial maximum. Sundalands includes the Malay Peninsula in mainland Asia and the continental islands (islands situated onto the Sunda Shelf) of Borneo, Java, Palawan, and Sumatra and their surrounding smaller islands. Each one montane taxon belonging to the mainland Asian genera Saturnia and Rinaca occur in Peninsular Malaysia, too. Those are Saturnia cameronensis LEMAIRE, 1979 and Rinaca thibeta pahangensis PAUKSTADT & PAUKSTADT, 2005. Further taxa are distributed in the northern Malay Peninsula but do not cross the Isthmus of Kra southwards. Those are Cachosaturnia cachara (MOORE, 1872) (Caligula), Rinaca lesoudieri LE MOULT, 1933, and Rinaca simla (WESTWOOD, 1847) (Saturnia). Regarding the present-day subgeneric distribution of Saturnia, cf. Rubinoff & Doorenweerd (2020); unfortunately the authors omitted the presence of the genus Rinaca in Peninsular Malaysia.
The genus Actias LEACH in Leach & Nodder, 1815 occurs in mainland Asia, the Andamans, Taiwan, Hainan and the Malay Archipelago, but the taxa of the felicis-, sinensis-, and dulcinea-groups of this genus do not occur in the Malay Archipelago at all. Loepa MOORE, 1859 is a further genus widespread in mainland Southeast Asia and the Malay Archipelago. But the oberthuri-group, the miranda-, damartis-, and the yunnana-subgroups of the miranda-group of Loepa are absent in mainland Southeast Asia and the Malay Archipelago, except a single taxon of the miranda-subgroup which occurs in Peninsular Malaysia, too.
Certain species or species-groups remain in Sundaland and had never crossed the Isthmus of Kra on the Malay Peninsula to the north. Those are taxa of the Sundaland-subgroup of the elaezia-group of the genus Cricula WALKER, 1855, the subgenus Loepantheraea TOXOPEUS, 1940 of the genus Antheraea HÜBNER,  1816, and the larissa-subgroup of the paphia/frithi-group of the subgenus Antheraea HÜBNER,  1816. There might be two reasons possible why certain taxa either never cross the Isthmus of Kra or have since become extinct. One might be caused due to the relatively small landbridge with restricted access to the region behind the Isthmus of Kra. That means passing the Isthmus from inland Southeast Asia to Sundaland and vice versa. Single taxa that happened to pass this bottleneck occasionally might have since become extinct due to the loss of their genetic variability (bottleneck-effect). The second reason can be the circumstance that the Isthmus of Kra has been submerged during the warm periods when the sea level at the Isthmus of Kra has been up to 110 m higher in early Pliocene, cf. Parnell (2013) who studied the flora and Bohlen, Dvořák, Ślechta & Ślechtová (2020) who studied the distribution of freshwater fish in that region. A significant biogeographic devide on the Thai/Malay Peninsula assocciated with the Isthmus of Kra was reported, which might be as important as the Wallace’s Line in the Malay Archipelago. Since some taxa of the Saturniid fauna are highly dependent on its species specific flora, there will have been a natural barrier at the Isthmus of Kra for certain taxa of the Saturniidae to spread at times.
The distribution patterns of various taxa of the family Saturniidae BOISDUVAL,  1834 in mainland Southeast Asia (including Taiwan, Hainan, and the Andamans), the Malay Archipelago, and Australia (including Tasmania) obviously indicates dispersal of certain species-groups via former land-bridges and most probably island hopping during the Pleistocene but most probably not much earlier. As Rubinoff & Doorenweerd (2020) found for Saturnia the first splitting off in Saturnia took place already in early Miocene (-23.1 mya). That means that certain related ancestors of taxa of the family Saturniidae might have spread to the Malay Archipelago much earlier than in early Pleistocene (-5 to 6 mya). However, this can only have happened if islands and land bridges or island chains already existed at that early time. Especially the distribution of the maenas-group of the genus Actias in mainland Asia and the Malay Archipelago at least suggests a very early separation (isis and all plesiomorphic taxa of the groenendaeli-group) which might be followed by a secondary reinvasion from Sundaland during the glacials and permanent but interrupted gen-flow between the Greater Sunda Islands and mainland Southeast Asia by a single species only (maenas). There are also other species among the Saturniids that are likely candidates for an earlier first colonization of certain islands or archipelagos in the Malay Archipelago. Those are Samia peigleri NAUMANN & NÄSSIG, 1995 (montane, endemic to Sulawesi), Antheraea pratti BOUVIER, 1928 (endemic to Sumatra), Cricula sumatrensis JORDAN, 1939 (endemic to Sumatra), Cricula hayatiae PAUKSTADT & SUHARDJONO, 1992 (Flores) and the related taxa in the hayatiae-subgroup of the luzonica-group (sensu Paukstadt & Paukstadt 2019) (endemic to the Eastern Lesser Sunda Islands), the ancestor(s?) of the cordifolia-subgroup (sensu Holloway, Naumann & Nässig 1996) (Sulawesi) of the paphia/frithi-group (sensu Nässig 1981), and the ancestor of the so far four species of the groenendaeli-complex (sensu Paukstadt & Paukstadt 2020) (Lesser Sunda Islands) of the maenas-group (sensu Nässig 1994). Ylla, Peigler & Kawahara (2005) proposed that the closest extant relative of Actias groenendaeli ROEPKE, 1954 might be Actias rhodopneuma (RÖBER, 1925). We suspect that there are probably even two separate ancestors of the cordifolia-subgroup. Those are an ancestor for A. cordifolia WEYMER, 1906 itself due to the morphology of the female antennae and an ancestor for the minahassae NIEPELT, 1926–complex, named after the oldest available name in the cordifolia-subgroup which contains highly variable wild silkmoths endemic to Sulawesi. Attacus lorquinii C. & R. FELDER, 1861 or its ancestor from the northern Philippines most probably represents a very early taxon of this genus in the Philippines, while A. caesar MAASSEN,  approached the southern Philippines from Borneo via the Sulu Islands much later. This theorie is supported by comparisons of the larval morphologies of both taxa and of those from taxa of the genus Attacus from Palawan and Borneo and distribution in the Philippines. Until now, only the geographical conditions during the Pleistocene have been considered, i.e. the distribution of the overseas land mass in the Malay Archipelago during either the warm or cold periods (Pleistocene).
The situations become more complex, however, if the time before the Pleistocene is also taken into account, i.e. times since the decay of Gondwana about 145 Ma ago, cf. Grabert (1991). By the way, some of the oldest fossilized insects are about 300 Ma old. Those are species of the now extinct genus Meganeura BRONGNIART, 1885 (giant dragonflies), cf. Nel et al. (2009, 2012). The island of Palawan could only have served as a land bridge between Borneo and the northern Philippines (Luzon) from around -10 mya, i.e. in the late Miocene, since Palawan was still drifting overseas in the South China Sea southwards to its current position in the early and mid Miocene. In the late Miocene, the islands of the Sulu Archipelago could have been used for island hopping between North Borneo and an island which is known as Luzon today. The southern Philippines had not docked at the time, but drifted from northeast off Sulawesi in a northwesterly direction towards Luzon. Some landbridges from the Asian mainland to the Malay Archipelago and in between the islands of the Malay Archipelago exist very late from early Pliocene (-5 mya). General information on the earth history and continental drift are provided by Diercke Maps (2015) and by Thenius (2012).
Various authors reported hotspots for wildlife biodiversity in mainland Southeast Asia and Borneo, cf. Venner (2017). Venner (2017) reported that SE Asia is home to an extraordinary 20% of global plant, animal and marine species and boasts four biodiversity hotspots. Those are the Kui Buri National Park (Thailand), Ba Bể National Park (Vietnam), Nakai Nam Theum National Biodiversity Area (Laos), and the Kinabalu National Park (Borneo). Regarding to the number of species of the wild silkmoths we identify further hotspots for Sumatra and New Guinea based on the number of distinct taxa in the family Saturniidae. At the time present approximately 50 species of the Saturniidae are known for Vietnam, 30 species for Thailand, 23 species for West Malaysia, 25 species for Borneo, 29 species for Sumatra, 17 species for Java, 18 species for Sulawesi, 7 species (including 2 taxa of the Papuan-Australian fauna) for Ambon and Seram, 6 species for Timor, 5 species (including 5 taxa of the Papuan-Australian fauna) for the Aru Archipelago, each 2 species (including each 1 taxon of the Papuan-Australian fauna) for the Kai Archipelago and the Tanimbar Archipelago. The distribution pattern of the taxa of the Saturniidae shows an evidently rapidly decreasing number of taxa from mainland Southeast Asia towards the eastern (Papuan) border of the Moluccas. On the other hands approximately 22 taxa of Saturniidae are known from Australia, 62 taxa from New Guinea (including 6 taxa of the Attacini), and 21 taxa of the Papuan-Australian Saturniidae are known from smaller islands outside of Australia and New Guinea (including the Solomon Islands, New Britain, New Caledonia, and the Moluccas). It is interesting to note that all six Saturniid species thus far recorded for the island of Timor (Eastern Lesser Sunda Islands) belong to Oriental genera, although the island has been located only about 90 km off the Sahul Shelf and therefore very close to Australia during the cold periods. Timor was not at all influenced by the Papuan-Australian fauna, at least as far as the Saturniids were concerned. The northern common cuscus (Phalanger orientalis PALLAS, 1766), a marsupial known from Timor is thought to be introduced, cf. IUCN Red List of Threatened Species. With the exception of Attacus LINNAEUS, 1767 no taxon of any wild silkmoth genus had managed to spread from Southeast Asia (including the Malay Archipelago) to New Guinea or Australia during the Pleistocene or more recently. While the adelphotaxon of Coscinocera BUTLER, 1879 might be Attacus, so far no obvious adelphotaxa can be found for any other genus of the Papuan-Australian fauna in the Malay Archipelago or mainland Southeast Asia. It cannot be ruled out that one or more ancestors of the Papuan-Australian taxa of the Saturniidae even might have originated from southern Gondwana. The fact is that related marsupials are known from Australia and from Chile (South America) and may therefore have had common ancestors in southern Gondwana. From Chile three species of the Chilean Rat Opossums of the genus Dromiciops THOMAS, 1894 (Microbiotheriidae) are known, which are closely related to Australian taxa, cf. D’Elia et al. (2016). Likewise, the ancestors of the ancient Araucaria family Araucariaceae HENKEL & W. HOCHST. of the Coniferales were spread throughout Gondwana and are now extinct in the northern hemisphere and in Africa. Descendants are still common in New Caledonia, New Zealand, Norfolk Islands, Australia, West Malaysia, and South America (Chile, Argentina, southern Brazil), cf. Tudge (2006), and The Gymnosperm Database (last time accessed 09 Sep 2020). In the Malay Archipelago members of the genus Araucaria JUss. occur on the island of New Guinea only. Also noteworthy is the distribution of the plant genus Nothofagus BLUME (Nothofagaceae) in the southern hemisphere in southern South America and the Australian region (including New Guinea). The seeds of the ancestors of these trees were found in Antarctica but not in the northern hemisphere, cf. Thenius (2012).
Extreme geographic changes occurred in the Malay Archipelago during the glacials. The falling sea level caused the continental islands on the Sunda Shelf to merge with the Southeast Asian mainland. The same happened with islands of the Sahul Shelf. Flora and fauna were able to disperse via the dry shelf regions that means invasion towards the former islands and probably reinvasion as well took place. During the warm periods, these islands separated again from mainland Southeast Asia or Australia and isolated the flora and fauna on them. This happened several times during the Pleistocene. The high biodiversity and the high number of endemic species in the family Saturniidae in the Malay Archipelago are the result of the high diversity of habitats on certain islands and still intact natural ecosystems. Depends on the soil and climate all types of vegetation can be found on various islands, from mangrove swamps, lowland forests, tropical rain forests, deciduous forests to mountain forests beside grassland, dryland, moors, and savannah. Different taxa of the Saturniidae have adapted to this great variability of habitats in various ways.
Some possible directions of dispersal can be shown here. We assume the spread from west to east in taxa of the Oriental fauna. An assumed spread from mainland Southeast Asia then inevitably took place via the Malay Peninsula and Borneo to the Philippines, whereby two routes were possible, namely via Palawan and Mindoro or via the Sulu Islands and Mindanao. Another route led through Borneo and Central Sulawesi to the central Moluccas. During the ice-ages the distances via the open sea between Borneo and Central Sulawesi have been approximately 45 km only. There has been a good chance for island hopping (by chance rather?) of certain taxa. Finally there has been a southern route via Sumatra, Java and Bali to the Lesser Sunda Islands concluded from the distribution pattern of some taxa. Several maps are included this work. The attached maps are selfexplanatory and might show that dispersal of the Saturniidae took place by chance rather than as targeted dispersal.
Overall, the preparatory work for this compilation and finally the attempt to document the biodiversity and possible directions of dispersal among the Saturniids in the Malay Archipelago had shown that although the number of species described had increased rapidly in the last two decades, this did not necessarily lead to a considerable improvement to general knowledge the Saturniids. There are still very large gaps in knowledge the biology and ecology of the Saturniids, and the distribution limits of individual taxa have also not been adequately researched."