Rene Tänzler; Katayo Sagata; Suriani Surbakti; Michael Balke; Alexander Riedel

“ Objective clustering of a refined dataset (excluding nine cryptic species) at 3% threshold revealed 324 genetic clusters (DNA group count relative to number of morphospecies = 20.0% overestimation of species diversity, or 120.0% agreement) and 85.6% taxonomic accuracy (the proportion of DNA groups that “perfectly” agree with morphology-based species hypotheses) . Agreement and accuracy were best at an 8% threshold. ”

“ GMYC analysis revealed 328 entities (21.5% overestimation) with 227 perfect GMYC entities (84.1% taxonomic accuracy) . Both methods outperform the parataxonomist (19% underestimation; 31.6% taxonomic accuracy) . The number of species found in more than one sampling area was highest in the Eastern Highlands and Huon (Sørensen similarity index 0.07, 4 shared species) ; 1⁄3 of all areas had no species overlap. Success rates of DNA barcoding methods were lowest when species showed a pronounced geographical structure. In general, Trigonopterus show high α and β-diversity across New Guinea. ”

“ The current inventory of 279 species is far from complete; even for the localities sampled, not all species have been discovered. Old museum specimens representing additional species from the Cyclops Mountains and the Balim Valley are already on hand, and most of the 13 divergent clades represented by females could probably be added to the species count after males with their diagnostic characters are found (and can easily be assigned to their females using cox1 sequences) . Thus, the number of species is likely to increase with additional sampling efforts, even in the same localities. ”

“ However, a taxonomic accuracy of 100% is achieved only when all morphospecies are fully congruent with the molecular groups and vice versa. In practice, high agreement means that the number of cox1 clusters or entities reflects species diversity as defined by an expert taxonomist well, and cox1 sequencing delivers a reasonable proxy for a fast, initial measure of diversity in a sample. High agreement does not neccesarily mean that most or all molecular units directly translate into species. Agreement-values exceeding 100% signal overestimation of species numbers, e.g. ”

“ In the final step, analysis of cox1 data stimulated the taxonomist to rethink species boundaries, accepting the existence of nine cryptic species that raised the total number to 279 species.
Because of the high number of morphologically similar species, sorting morphospecies across different localities is very difficult, even for highly trained experts. ”

“ These data assume that the final species hypotheses are correct; however, an overestimation of species diversity, mainly involving allopatric populations, might also suggest that there are more Trigonopterus species in the dataset than we finally recognised. Here, more sampling and a research program focused on population genetic processes and other lines of evidence would be needed to arrive at sound taxonomic conclusions. ”

“ Haia and Supa support lower and mid-montane forests, while mid- and upper montane forests dominate the localities in the North. Aiyura, Goroka, and Okapa have Sørensen indices similar to the localities in the Balim area. Only two of the seven species shared between them, had intraspecific p-distances above 2%. However, five of the eight allopatric species in Balim had high intraspecific p-distances (2.05–8.79%) , resulting in a lower success rate from clustering (see above) . The ecology of the species collected could be an important factor as well ”

“ Trigonopterus weevils are hyperdiverse across the island of New Guinea, with high α- and γ-diversity. Their ß-diversity is very high, as expected from samples that mainly originate from different mountain ranges. Despite denser sampling across the island, we still find comparably deep branching patterns between species, with an average interspecific cox1 divergence of approximately 20% (range 12–24%) . ”

“ For comparison, we used relative values, calculating percentages out of the absolute number of clusters found for each of the 12 clustering thresholds.
Final species hypotheses
These were arrived at by studying the distribution of refined morphospecies hypotheses among the molecular entities (Fig. 3; Table 1) . Morphospecies with high cox1 divergence were examined morphologically a second time (see Table S3) , and nuclear DNA markers were sequenced to discover potentially diagnostic nDNA characteristics that suggest the existence of “cryptic” species or reveal overlooked species. ”

“ How often are ecologists wrong and when does it matter? Ecol Monogr. 2010;80:267–286. doi: 10.1890/09-0267.1↑ Riedel A. One of a thousand - a new species of Trigonopterus (Coleoptera, Curculionidae, Cryptorhynchinae) from New Guinea. Zootaxa. 2010;2403:59–68.↑ Pinzón-Navarro S, Barrios H, Múrria C, Lyal CHC, Vogler AP. DNA-based taxonomy of larval stages reveals huge unknown species diversity in neotropical seed weevils (genus Conotrachelus) : relevance to evolutionary ecology. ”

“ The tools are ready; it is now up to conservationists to use them.
Supporting Information Figure S1 Maximum likelihood tree based on '''cox1''' sequences of 1,002 specimens of '''Trigonopterus'''. Seven outgroup representatives are included. Specimens come from seven areas of New Guinea. Clusters correlate with the assignment of 270 morphospecies given to the right and nine additional cryptic species marked in red. The dataset in nexus format is available from the authors. ”

“ The land of the Orang-Utan, and the Bird of Paradise. Anarrative of travel, with studies of man and nature. London: Macmillan & Co. Vol. 1: 312 p.; Vol. 2; 1869. ↑ Wilson EO. Adaptive shift and dispersal in a tropical ant fauna. ”