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Home My WebLink AboutFriday-Ceratocystis_wilt_for_GMAC2017rev2Ceratocystis wilt of ‘Ōhi‘a (Rapid ‘Ōhi‘a Death): A slow fire in Hawaii’s native forest J. B. Friday and Corie Yanger (UH Mānoa CTAHR Cooperative Extension Service) Kamaili Road 1 The ROD squad: a team effort USDA Forest Service: Flint Hughes, Christian Giardina, Kealoha Kinney, Phil Cannon, Sheri Smith, Leif Mortenson, Ric Lopez, Travis Sowards, Ardena Saarinen, Kainana Francisco, Jenny Juzwik USDA ARS: Lisa Keith, Lionel Sugiyama, Wade Heller, Marc Hughes HDOA: Rob Curtiss, Wil Guerrero, Ken Dumalo, Amy Takahashi, Clayton Nagata, Clare Okumoto, Lance Sakaino DLNR DOFAW: Rob Hauff, Philip LaHaela Walter, Steve Bergfeld, Jay Hatayama, Anya Tagawa Students and interns: Blaine Luiz (UH Hilo), Kyson Dunn (HCC), Nathanael Friday (Dartmouth College) USGS: Lloyd Loope, Jim Jacobi, Carter Atkinson, Gordon Tribble, Lucas Fortini CTAHR: Gordon Bennett, Curtis Ewing HISC: Josh Atwood CGAPS: Christy Martin TNC: Evelyn Wight CAO: Greg Asner BIISC/MISC/OISC: Springer Kaye, Frannie Brewer, James Parker, Bill Buckley, Rachel Neville, Chuck Chimera Iowa State: Tom Harrington FABI: Mike Wingfield 2 There has been a noticeable increase in ‘ōhi‘a forest mortality in the Puna district of Hawai‘i Island over the past 6 years 2008 2012 3 Signs and Patterns Begins in small patches of 10 to 50 trees Browning of crown within weeks, sometimes within days, and eventual defoliation Large, healthy, mature trees also affected No external signs of a fungus 4 Native ‘ōhi‘a forest near Pahoa, 2005 5 2015 6 Wao Kele o Puna Strawberry guava Wao Kele o Puna Extent of the problem. Example of the rules guava plays as invasive species worldwide 7 Native Forest at 3,500 ft, Upper Wailuku River above Hilo Tree fern understory 8 2017 9 Hawaii DLNR Division of Forestry and Wildlife and USDA Forest Service 2016 aerial sketch map 47,000 acres affected 10 Field Sampling Lisa Keith, Wade Heller, Marc Hughes USDA ARS Sketch, tree map and pictures by Kyson Dunn and Blaine Luiz 11 Other ‘Ōhi‘a Forest Health Issues Landscape-scale ‘ōhi‘a dieback was investigated in the 1980s and found to be linked to cohort senescence. ‘Ōhi‘a rust (Puccinia psidii) primarily affects new sprouts and leaves. Root rot in HVNP Branch cankers Drought and vog- caused mortality in Ka‘u and South Kona 12 Isolation & Identification of the Pathogen Molecular analysis Growth & morphology Two new species of fungal pathogen Ceratocystis Not found elsewhere Currently being described and renamed 13 Where did they come from? B A ? ? http://www2.padi.com/blog/2011/05/02/teach-your-child-to-conserve-our-oceans/hawaii-map/ 14 Pathogenicity Tests 1 2 3 4 5 6 7 Recreate the signs Re-isolate the pathogen 15 Sketch and pictures by Kyson Dunn & Blaine Luiz Epidemiology How/where does the tree get infected? Are wounds necessary? How many spores cause disease? How does disease progress over space and time? 16 http://en.wikipedia.org/wiki/Ceratocystis_fimbriata Host Susceptibility Testing Other ‘ōhi‘a varieties and species 17 Temperature and Growth ? ? 18 Temperature and survival Photo credit: Lionel Sugiyama 24C (75F), 7 days 24C (75F), 3 days 35C (95F), 10 min, 7 days 35C (95F), 10 min, 3 days 47C (117F), 10 min, 3 days 47C (117F), 10 min, 7 days 50C (122F), 10 min, 3 days 50C (122F), 10 min, 7 days 19 How does the pathogen move? Long distance: People moving wood, firewood, posts 20 How does the pathogen move? Insect frass Soil Vehicles 21 Wind dispersal of infected frass 22 Wounds as infection sites 23 Which beetles are out there and do they carry the disease? Trapping beetles on ‘ōhi‘a trees Trapping beetles in the forest Almost all one species Molecular detection of ROD 10% of beetles from ʻōhiʻa trees test positive Next questions: are beetles able to infect healthy ‘ōhi‘a? Environment ʻŌhiʻa 24 Beetle infestations mostly on newly killed trees (6 months to 2 years) Not on older trees 25 Management strategies Don’t move ‘ōhi‘a wood or plants! 26 Don’t wound ‘ōhi‘a trees 27 Clean mud off gear, wash with detergent 28 Decontaminate cutting tools 10% chlorine bleach, 70% isopropyl (rubbing) alcohol, 90% ethanol: 15 seconds NOT Simple Green 29 Wash vehicles (inside and out) 30 What to do with infected dead trees? IF they are on the leading edge Cut them down Cut them up Don’t let sawdust blow around Cover with a tarp (3-6 months) Or burn them in a fireplace, smokehouse or imu! Don’t move the wood County assistance with disposal of wood? County arborist to advise? 31 County Greenwaste and composting 160 oF 32 Hawai‘i Department of Agriculture Rules No movement of ‘ōhi‘a plants or plant parts including flowers, leaves, seeds, stems, twigs, cuttings, “untreated” wood, logs, mulch, greenwaste, and frass (sawdust from boring beetles) from Hawai‘i Island Except by permit from HDOA (Permanent as of Nov 2016) 33 Rapid ‘Ōhi‘a Death Symposia March 18, University of Hawai‘i at Hilo April 1, West Hawai‘i Community Center 34 www.RapidOhiaDeath.org 35 3,580 likes 36 Extra Slides 37 Other ‘ōhi‘a diseases Cylindrocladium, a foliar disease in South Kona 38 Other ‘ōhi‘a diseases Branch cankers 39 Wounding by feral cattle “Cattle hunt road”, Hilo Forest reserve 40 Greg Asner 41 42 43 44