Native Cillaeine Sap Beetles (Coleoptera: Nitidulidae: Cillaeinae) in French Polynesia; Diversity and Biogeography Author: Curtis Ewing Environmental Science, Policy, and Management University of California Berkeley Presented by Peter Oboyski Environmental Science, Policy, and Management University of California Berkeley Sap Beetles family Nitidulidae Subfamily Cillaeinae • Cillaeine Sap Clubbed Antennae beetles in French 4-8 mm Polynesia can be recognized by: Exposed Abdomen Flattened and parallel sided Species endemic to • Marquesas (19 spp.) • Tahiti (1 sp.) • Separated by 1,400 km • All Undescribed • Tahiti species closely related to Marquesas species 19 Marquesan species 0 • 18 of 19 are single island endemics 8 1 • Nuku Hiva – 8 spp. 4 • Ua Huka 4 – 1 sp. 6 • Ua Pou 1 – 4 spp. 0 0 • Hiva Oa 0 – 6 spp. 0 • 1 sp. also found on Tahuata (1 specimen) Native Sap Beetles All found at high elevations in cloud forests • Associated with specific plants • Plants tissues do not directly supply nutrients • Beetles consume fungi that grow on decaying substrate – Some sap beetles have been shown to vector specific fungi internally • Depend on constant moisture to thrive Temetiu Ridge, Hiva Oa TAHITI • One widespread species • Relatively common in all wet and cloud forests with significant native vegetation TAHITI • Plant Hosts • In decaying stipes of tree ferns (adults only) – Cyathea spp. (common) – Angiopteris evecta (rarely) TAHITI • Plant Hosts – under bark of Reynoldsia (adults and larvae) TAHITI • Arlequin was used to analyze 25 co1 sequences (658 bps) • Specimens from around island • Specimens from both hosts when available (Reynoldsia in proper state of decay rarer) – No population structure • No host effect • No geographical effect Nuku Hiva • 8 new species collected in 2007 – 1 associated with Cheirodendron bastardianum – 7 associated with decaying Cyathea stipes • All from Tekau ridge (980-1120m) – Cyathea associated species found sympatrically, mixed species in single frond • Cyathea below 980 m full of invasive species Ua Pou • 4 species all historically known from Cyathea stipes – 1 species collected in 2007 from Freycinetia: Decay facilitated by rat damage • 2 in fruit • 1 in leaf axil – Only specimens found in French Polynesia associated with Freycinetia: driven to suboptimal host by drought?? – Other 3 spp. Not found in 2007 Hiva Oa • Historically found on 3 hosts – Cheirodendron bastardianum – Crossostylus biflora – Cyathea spp. • All hosts sampled extensively in 2007 – Decay seemed appropriate on all • Specimens only found in association with Cyathea in 2007 • 6 species collected • All historical species apparently recollected – Multiple specimens of all species, none especially rare Ua Huka and Tahuata • Historical specimens only (1930s) • Ua Huka: 2 historical specimens of one species endemic to the island • Tahuata: 1 historical specimen from banana appears to be the same as one of the Hiva Oa species from Temetiu, which is approximately 12 km from the collection site on Tahuata. Nuku Hiva species ancestral to Hiva Oa species in 2 cases This is consistent with a pattern of colonization from older (Nuku Hiva 3.8 my) to younger island (Hiva Oa 1.9 My) Tahiti Only one Tahitian species Ancestral to major clade Inconsistent with island age, Tahiti only 0.8 my old Relatively recent arrival from?? Ua Pou Only one species included Ancestral to large Nuku Hiva-Hiva Oa radiation Inconsistent with island age, Ua Pou 3.2 my vs. 3.8 for Nuku Hiva Conclusions • 20 cillaeine species to be described – 16 collected during 2006-2007 survey – 8 represent new records (all from Nuku Hiva) • Single Tahitian species genetically diverse – No population structure – No speciation – Strong dispersal within island? – Relatively recent arrival? • 2 cases of dispersal from Nuku Hiva to Hiva Oa • Both between island and within island speciation apparently common • Possibly colonized between formation of Ua Pou (3.2 my) and Hiva Oa ( 1.9 my) • 19 of 20 species single island endemics Acknowledgements • Rosie Gillespie and George Roderick • National Science Foundation: French Polynesia Terrestrial Arthropod Survey Grant • Richard B. Gump Station, Moorea • Jim Liebherr, Dan Polhemus, Elin Claridge, Pete Oboyski, David Hembry, Jean-Yves Meyer, Rava Taputuarai and Shane McEvey for support, specimens, and company in the field.