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bannork

Can I prevent this on my Siamese Rosewood tree?

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There are these black areas on the trunk where some kind of flying insect enjoying what I assume is sucking the sap out of the tree. I tried spraying the areas with a mosquito repellent but the insects were soon back. Has anyone any ideas?

Yours Bannork.

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Posted (edited)

You assumption may be a little off, as is the treatment.  The condition appears to me to be signs of wounding and tree response to a bacterial infection, or more likely, a beetle borer, or clear-wing moth borer, that has invaded the tree trunk to feed and/or lay eggs which when hatched become larvae that feed on the internal tissues.

If you see flying insects around the external sites, they could be secondary (not the cause) and are attracted to the sugary alcoholic exudate. 

Does the foliar canopy appear healthy or is there branch dieback?  

 

Some borers are more destructive to the host tree than others. Some invade and do minimal damage, come and go. Some test the tree but don't propagate and become a major infestation.  But some adult beetles and especially their larvae do extensive boring and form galleries that cut off the sap flow between roots and foliage, eventually causing top dieback or death of the tree. Some borers introduce fungal pathogens that grow inside the tree and do major damage.

 

Many borer infestations are brought on by water deficit, drought stress, that makes trees vulnerable to infestations. Nutrient deficiencies can contribute to susceptibility. Be sure to manage soil and water adequately.  

 

I don't know the common pests of this rosewood tree. But a general treatment for borer prevention may stop the infestation. In some cases, adult beetles emerge after pupation and fly back to the same tree or nearby trees of the same species. Applying a protective insecticide barrier to the external area of the tree trunk that is being affected, will discourage beetles from further activity in that tree. Killing the adults or larvae that are already inside the tree is not practical, but preventing more activity is a very successful way to deal with it. Although mine is not a positive diagnosis, just a best guess from seeing your photos. 

 

This treatment is called "trunk banding" or "basal bark treatment". It involves mixing and applying by sprayer, of a solution of a strong contact and residual action insecticide (not a systemic) to the bark surface around the lower trunk where the pest activity is present. 

 

My choice would be a pyrethroid (synthetic chemical form of the old standard botanical insecticide, pyrethrum or pyrethrins.) Pyrethroids are not organic program compatible, but are least toxic and by method of application there is not a lot of environmental exposure. It is sprayed on the lower tree trunk only where the activity is located, and binds with the bark to provide a protective coating. It is not a foliar canopy spray. Manage to prevent heavy overspray and spills.

 

I would use permethrin, cypermethrin or bifenthrin.  Bifenthrin has the longest residual effectiveness. it is the active ingredient in the widely available Chaindrite Stedfast 30SC. Lotus with mosquito sprays, HomePro garden section and others. Ask for "ya ka maleng". 

Mix 100 to 150 ml per one liter of water in a hand-held pump up sprayer or backpack sprayer. Yes it needs to be a strong solution in order to get full season residual effectiveness.  Spray the tree trunk to the point of runoff. Protect yourself from skin, eye and respiratory exposure. Once on the tree and dried the area can be re-entered by people and pets and farm animals. 

 

https://www.toagroup.com/en/product/product-details?url=chaindrite-stedfast-30-sc

 

By the way, mosquito repellent sprays are weak solutions with a very short residual effectiveness, a few hours to a day at most.  

 

I hope this helps. Please post follow up information and photos. 

 

You may be aware that you have a very valuable tree of an endangered species. 

https://www.newsweek.com/2017/08/18/siamese-rosewood-tree-thailand-poachers-646904.html

 

 

 

Chaindrite Stedfast 30 SC.jpg

Edited by drtreelove

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8 hours ago, drtreelove said:

You assumption may be a little off, as is the treatment.  The condition appears to me to be signs of wounding and tree response to a bacterial infection, or more likely, a beetle borer, or clear-wing moth borer, that has invaded the tree trunk to feed and/or lay eggs which when hatched become larvae that feed on the internal tissues.

If you see flying insects around the external sites, they could be secondary (not the cause) and are attracted to the sugary alcoholic exudate. 

Does the foliar canopy appear healthy or is there branch dieback?  

 

Some borers are more destructive to the host tree than others. Some invade and do minimal damage, come and go. Some test the tree but don't propagate and become a major infestation.  But some adult beetles and especially their larvae do extensive boring and form galleries that cut off the sap flow between roots and foliage, eventually causing top dieback or death of the tree. Some borers introduce fungal pathogens that grow inside the tree and do major damage.

 

Many borer infestations are brought on by water deficit, drought stress, that makes trees vulnerable to infestations. Nutrient deficiencies can contribute to susceptibility. Be sure to manage soil and water adequately.  

 

I don't know the common pests of this rosewood tree. But a general treatment for borer prevention may stop the infestation. In some cases, adult beetles emerge after pupation and fly back to the same tree or nearby trees of the same species. Applying a protective insecticide barrier to the external area of the tree trunk that is being affected, will discourage beetles from further activity in that tree. Killing the adults or larvae that are already inside the tree is not practical, but preventing more activity is a very successful way to deal with it. Although mine is not a positive diagnosis, just a best guess from seeing your photos. 

 

This treatment is called "trunk banding" or "basal bark treatment". It involves mixing and applying by sprayer, of a solution of a strong contact and residual action insecticide (not a systemic) to the bark surface around the lower trunk where the pest activity is present. 

 

My choice would be a pyrethroid (synthetic chemical form of the old standard botanical insecticide, pyrethrum or pyrethrins.) Pyrethroids are not organic program compatible, but are least toxic and by method of application there is not a lot of environmental exposure. It is sprayed on the lower tree trunk only where the activity is located, and binds with the bark to provide a protective coating. It is not a foliar canopy spray. Manage to prevent heavy overspray and spills.

 

I would use permethrin, cypermethrin or bifenthrin.  Bifenthrin has the longest residual effectiveness. it is the active ingredient in the widely available Chaindrite Stedfast 30SC. Lotus with mosquito sprays, HomePro garden section and others. Ask for "ya ka maleng". 

Mix 100 to 150 ml per one liter of water in a hand-held pump up sprayer or backpack sprayer. Yes it needs to be a strong solution in order to get full season residual effectiveness.  Spray the tree trunk to the point of runoff. Protect yourself from skin, eye and respiratory exposure. Once on the tree and dried the area can be re-entered by people and pets and farm animals. 

 

https://www.toagroup.com/en/product/product-details?url=chaindrite-stedfast-30-sc

 

By the way, mosquito repellent sprays are weak solutions with a very short residual effectiveness, a few hours to a day at most.  

 

I hope this helps. Please post follow up information and photos. 

 

You may be aware that you have a very valuable tree of an endangered species. 

https://www.newsweek.com/2017/08/18/siamese-rosewood-tree-thailand-poachers-646904.html

 

 

 

Chaindrite Stedfast 30 SC.jpg

Thank you for you very detailed response drtreelove. Actually chaindrite was the substance I tried yesterday. I used the orange cans sold everywhere mainly for killing termites. Still, the insects were back today. The tree does have some leaves in the canopy and it does get watered frequently.

I have over a dozen พยุง most about 10 years old. The missus scolded me saying I would never be able to sell them legally but recently the government changed the law, allowing private citizens to grow and sell them.

I've always found them a hardy tree, I've occasionally found a sapling that has grown from the seed of the parent tree that hasn't been watered the entire six months dry season yet has not died 

Still, I'm worried about this tree because another payung, near this one, died last year of no apparent reason.

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 Do a Google search on ต้นพยุง มีปมลง. There are several YouTube videos that discuss insect/disease problems with your type of tree

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4 hours ago, bannork said:

Thank you for you very detailed response drtreelove. Actually chaindrite was the substance I tried yesterday. I used the orange cans sold everywhere mainly for killing termites. Still, the insects were back today. The tree does have some leaves in the canopy and it does get watered frequently.

I have over a dozen พยุง most about 10 years old. The missus scolded me saying I would never be able to sell them legally but recently the government changed the law, allowing private citizens to grow and sell them.

I've always found them a hardy tree, I've occasionally found a sapling that has grown from the seed of the parent tree that hasn't been watered the entire six months dry season yet has not died 

Still, I'm worried about this tree because another payung, near this one, died last year of no apparent reason.

Chaindrite is the name of the company that produces many insecticides etc. The one you used contains permethrin, which as you say is very effective against termites etc. 

However, without actually viewing the tree in situ, the tree is already in an unhappy condition, and as drtreelove says, this is probably visible evidence of a physiological disease of the tree, which may have been present for a few years.

My first reaction would be to look if the tree has been attacked years ago by a maniac Thai tree lopper, leaving open wounds etc.(happens not only in Thailand).

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Thanks for all the advice folks. I tried an insecticide recommended by the local town shop- no effect, tried a จุลินทรีย์  mixture I made( recommended by a Youtuber- zero effect. Finally, another Youtuber, on the link provided by koksaat, tried pieces of mothballs inserted into the holes on the trunk dug by the insects and then covered with plastic around the tree. I liberated that from the local Big C though I did pay for the mothballs, 42 baht. So far success, no more flying insects sapping the sap out of the tree. Now I have to see if they'll bore other holes in the trunk not covered by the plastic. The tree itself has plenty of foliage, what with the recent rain and my watering it every 2 days. I'll post some photos soon.

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I'm the first to admit the plastic is unsightly, but with the mothballs underneath it seems to have done the trick for now.

This first pic shows some pieces of a  mothball near a hole at the base of the trunk where the insects were sucking the tree's resin. I covered the hole with soil and stones and left the pieces to deter them. So far, so good. The second pic shows the good foliage.

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