Ohia trees are dying rapidly, Why?

[Rene Siracusa]

Per J.B.Friday, extension forester with UH Cooperative Extension Service, the culprit now appears to be a fungus called Cytophtera (sp?).
This fungus has been around for a while affecting other plants, but has only recently been identified in relation to 'ohia.

JB will give a presentation about Rapid 'Ohia Death and this fungus and update us on current research and what can be done on Saturday, May 23 at 1:00 pm at the Pahoa Community Center. The presentation is sponsored by Malama O Puna and will be followed by MOP's annual general membership meeting. Interested persons may stay on for the meeting, whether or not they are members.

[pbmaise]

Rene
When poster Justin went JB Friday's presentation in Leilani, he came back with an impression that

"In the last year people have done a substantial amount of research and testing in order to determine the cause of the problem....however.. "

I am a bit cynical around the academic community. The newspaper interview with Friday, led us to believe this would take a long time to investigate. I read this as it will require years and lot of research $.

I want to accelerate the investigation so we might move quicker to a solution if one is possible. I keep imagining what Leilani will look like minus those beautiful trees.

Ohia have been in Hawaii a very long time and many are hundreds of years old. Something new must be attacking them.

Ceratocytis has been in Hawaii a long time already too. It attacks pineapple, taro and yams. Further, taro plants were immune In a study if they had no injury. The variety of Ceratocytis that causes oak wilt also requires injury first.

Oaks die mainly from oak wilt owing to a bettle that makes them susceptible. It is possible a newly arrived species of insect is injuring the Ohia first and then an existing Fungus gains entry.

After watching carpenter bees destroy a large Ohia post, I know they cause injury to Ohia. They or a bettle may be the vector. Didn't Gypsy mention bettles? Or could fire ants be at work. They injure plants too.

The difficulty with accepting Ceratocytis as the culprit is it requires two players. The fungus plus damaging insect.

Ohia are being infected from either above the soil level or below.

Since a newly arrived strain of Armillaria is proven to attack roots without needing the insect vector, it is less difficult for me to imagine. Further Armillaria has been tagged as a possible culprit since 1972.

I hope Friday is right and it is Ceratocytis.

Saving the Ohia then may become a question of eliminating an insect vector.

We can sit back and leave it to the experts, or we can be mobilized to assist.

People can drive by and look at stands of Ohia dying and ignore the problem or get out of there cars and go look for possible reasons.

The entire forest may soon be gone. That prospect is perhaps more scary than a lava flow.

http://en.m.wikipedia.org/wiki/Ceratocystis

To a degree I feel like I am shouting the sky is falling. However, just look up Dutch Elm Disease.

It is caused by a member of the
sac fungi (Ascomycota) affecting elm trees, and is spread by the elm bark beetle.

Only a few communities that actively protected the living trees have had any success.

Is anyone attempting any of the proven measures that protected elms to see if they will protect Ohia too?

[Justin]

The fungus is known, but the distribution is not. If it is an insect, or otherwise airborne, there is really no hope for existing trees. That's not me being negative, that's me being realistic. For a fungus that kills plants in less than a month, and moves quickly, coming up with a "solution" on the order of years is going to be too late, and that's just math.

I really think more should be done on the landscaping side, to grow fungus-resistant trees, either through selective hybridization and/or grafting Ohia trees onto other Metrosideros root stock.

Just my two cents.

[pbmaise]

Justin,
I reviewed this thread and found the problem has largely been ignored for years.

Gypsy started it 1.5 years ago

He said about 80% of Ohia around his house were dead.

He said this has slowly been happening for 4 years

5.5 years is a long time to only have a suspect fungus and no reason.

Researching the web more, I found Ceratocytis is a problem for cacao production.

Ceratocystis fimbriata lives in soil and can cause relatively sudden tree death. The fungus In Brazil has been recognised increasingly since
1998 and has been associated elsewhere with drought.

When a tree is infected or dies, Xyleborus beetles
bore into the branches. They push out from their tunnels frass. It is a light, powder and contains viable
inoculum of the fungus, which may be spread by wind.
This invasive beetle first arrived in US in 2002.


http://en.m.wikipedia.org/wiki/Xyleborus_glabratus

This changes the odds in favor of Ceratocytis because a new invasive species is already causing tree deaths on the mainland.

If the bettle can be found in Hawaii, especially on millions of dead Ohia, then we basically solved the question.

[pbmaise]

Wait,

While researching Xyleborus beetles, I learned they spread a second fungus.


The deadly fungus they are spreading In Florida and Georgia is called
http://en.m.wikipedia.org/wiki/Raffaelea_lauricola

It matches description of deaths in Ohia.

Protection of trees should be tried along same grounds as Florida?

Fix link

[pbmaise]

A list of recently arrived insect that could be vector delivery systems includes:


1. Fire ants - Known to injure roots and bore into trees to make chambers. 1999 timing is right.

2. Xyleborus beetles that recent destroy 10s of thousands of acres In Florida by transmission of a fungus. However, not confirmed yet in Hawaii?

3. Oriental flower bug beetle found in 2002 on Ohau Protaetia orientalis
The timing is right.

4. Coconut Rhinoceros Beetle
It is mainly know for destroying palms In general. It may be in Puna but likely not cause of Ohia problem. This said it is a serious threat to coconut and other palms. On Oahu there is an on-going aggressive management program. Up to 150 palms have been cut down in one area.

5. Carpenter bees that drill directly into Ohia. These may assist the another insect by first creating the holes, then another insect occupies the hole.

edit
Adjusted statement on rhino beetle

[Midnight Rambler]

Arrggghh...the amount of misinformation on this thread is agonizing. People, please, don't post stuff on here based on snippets you picked up from Wikipedia or from other places.

1) Little fire ants do not injure tree roots. They make very small nests, often up in trees, which is part of why they're so hard to control. You're thinking of the red imported fire ant (Solenopsis invicta), found in the mainland.

2) There are hundreds of species of Xyleborus beetles in the world; about 30 already occur in Hawaii, about 20 of them native. They mainly attack trees that are already injured; they bore into the trees and introduce a fungus that then spreads into the tree, and the beetles then feed on the fungus. Their relationship is with a specific fungus, so they might attack a tree already weakened by Ceratocystis, but it's not the one they would be spreading around.

3) The Oriental flower beetle feeds on flowers (as the name suggests), and has been here since the 1950s. It's sometimes a problem for mangos and other fruit trees but otherwise not a big deal, and has nothing to do with spreading fungal diseases. Likewise, coconut rhinoceros beetles are only found on Oahu, and eradication is being attempted. If you see any in Puna, report them (but don't mistake the flower beetles for CRB; somehow people keep doing so, even though they look very different).

4) Carpenter bees do not bore into live trees, only dead ones.

5) Mushrooms do not indicate the presence of a tree-killing fungus. Most fungi do not produce mushrooms to spread their spores; it's mostly decomposers that grow in the soil or decaying wood that do so.

[pbmaise]

One purose of the forum is to correct the misinformation that the public obtains when trying to investigate. Correcting misinformation is greatly appreciated.


1. Many websites state fire ants in general are omnivores. Can "remove bark and girdle trees".
Yes these websites do not say specifically LFA.

http://www.extension.org/pages/60922/wha...SJlZjPvCl4

So LFA are unlike other fire ants? I admit I lump all fire ants into one group.


2. I cite a specific Xyleborus beetle that is devastating Florida with up to 92% loss of all red bay trees. This beetle is certainly not going around looking for trees already stressed or infected. For your statement to be true, almost all existing Ohia trees must be already infected.
http://www.journaloffloridastudies.org/0...lwilt.html

"
Aside from fungicide protection of individual, high-
value landscape trees (Mayfield et al. 2008c), current
strategies for disease control rely on early detection of laurel wilt in a new area, followed by aggressive sanitation practices, such as removal and chipping of wilted trees.

When I pose open questions asking if any attempts are being made to do similar attempts to save Ohia all I hear is it will take years to learn for sure, so in the meantime do nothing.

This is not the approach in the ER. When the patient arrives and the heart is stopped, you start it again and then look for reasons.

I want us to eliminate the term die - back. That implies a natural episodal process. What is going on with Ohia now doesn't seem natural.

3. Agreed. However, I didn't know they were in Hawaii 50 years already. The invasion date of 2002 I found on a list invasive species to Hawaii . Also it is so typical of US Defense to claim they prevented an invasion of a bug already present. This said, I believe midnight rambler. Strike Protaetia orientalis from list. However just keep them in the back of your mlnd. Unlike the name implies, and midnight says, flowers are not their only food.

Protaetia orientalis feed on organic matter in the soil, and some species damage the roots of plants (Borror et al., 1989). They are on the suspect list in Guam as being responsible for deaths of ironwoods.

So certainly poke around the ground of dying ironwoods for beetles.

This article is very good and covers some bacterial issues too.
http://mysare.sare.org/mySARE/ProjectRep...o=viewRept&pn=SW08-067&y=2013&t=1



4. The claim carpenter bees bore only into dead wood is refuted by a website carpenterbees. com. Further I think it logical to claim they only bore into dead wood is the tree is dead and laying on the ground. The nests I observed were 12-16 feet off the ground.

5. The fungus under Gypsy's dead grass in the yard was a leap when considering the dead Ohia nearby.

[Rene Siracusa]

When JB Friday agreed to give a presentation on 5/23 he told me that he hoped to have some new info to impart based on some ongoing research. I hope so too. I do know that a lot of time and effort is being put into this problem and I can only hope that a 'cure' will be identified (and funded) in time to save our trees.

He did mention that not all ohia succumb - some seem to have a natural immunity or resistance. I asked him about propagating from those, in order to develop a resistant strain, and he said that that is one of the things being looked at.

[Carey]

Received this email on the vascular wilt fungus Ceratocystsis & a talk at Aupuni Center this Friday, June 5, 5pm
Dear Hawaii Island foresters and forest landowners,

A new, devastating disease of ohia has been attacking forests in Puna and is rapidly spreading to other parts of Hawaii Island. So far thousands of acres of trees have been killed. The causal agent has been identified as the vascular wilt fungus Ceratocystis, which causes similar diseases in related trees such as Eucalyptus but had never been found attacking ohia until last year. We do not know how the disease got here or how it spreads.

I will be giving at talk at 5:00 pm this Friday, June 5th, at the Aupuni Center in Hilo on what we have discovered so far about this new disease, what the symptoms are, and what preventative measures we recommend. The talk is sponsored by the Hamakua Soil and Water Conservation District and the USDA Natural Resource Conservation Service. If you plan to attend please let Kanoe Malani of the SWCD know by calling her at 808-933-8363 or emailing her at Kanoe.Malani@hi.nacdnet.net.

Because we are discovering something new about the disease almost every week, we have set up a website with photos and the latest information. The URL is www.ohiawilt.org. If you see the symptoms illustrated on the website and are outside of the core area (Hilo town and Puna district up to Volcano) I would like to know so that we can sample and track the progress of the disease. There are many pests and diseases of ohia, including drought and the Puccinia rust, but this is something new, and you all who know your forests will see the difference. "