Banana trees killed by bugs?

[THAIPHUKET]

It seems that our banana trees are succumbing to these creatures, slowly turning yellow and then breaking. If that is so, how to combat?

[CLW]

It seems that our banana trees are succumbing to these creatures, slowly turning yellow and then breaking. If that is so, how to combat?

I would say it's a banana weevil.

Biological control method is spaying with Beauveria bassiana fungi. You should be able to find that on the internet or by advertisements in agricultural magazines. It is available in Thailand.

Chemical control with Chlorpyrifos, Imidacloprid or Fipronil.

I would try biological control first

[THAIPHUKET]

much appreciated!

[CLW]

You're welcome.
Here is the detailed information

http://www.filehosting.org/file/details/669138/IN020179_eng.pdf

[CLW]

Just found this while browsing on Facebook

This shop has the Beauveria bassiana fungi besides some other biological control agents.

 

 

 

[THAIPHUKET]

Apologies for late reaction but thank you, that's more than can be expected. Greetings form Chiang Mai

[drtreelove]

I took this photo of beauveria at a shop in Mae Jo, Chiang Mai. If you are in that area I can give you directions. 

 

I haven't used this product, and didn't know about it's use for this weevil. But like all biological controls, the timing is important, you must know what stage of the life cycle of the insect pest that the product should be applied. It's like Bt, a lot of people waste their time and money thinking it can be used like a contact insecticide, but in fact it has to be applied when the larva stage is present and feeding, and more accurately when the larva at are the first and second instar stage. It has to be ingested by the younger larvae.  It won't harm later stage instar larvae, pupae or adults. So do a little research and find out how to use the beauveria before you buy it. 

 

That's what makes biological control, and other aspects of IPM more demanding for knowledge and experience. Most people take the easier no-brainer approach and use hard chemistry.  But even hard chemistry is important to get it right, for effectiveness and for safety of people, pets and the environment. 

 

In my opinion it is not appropriate to recommend chlorpyrifos, imidacloprid or fipronil for this situation. 

Chlorpyrifos is an OP (organophosphate). Older generation hard chemistry, very toxic and persistent in the environment.

http://www.panna.org/take-action/follow-science-chlorpyrifos-epa?gclid=CKWO3bqqpdQCFURqfgodYUIITQ

 

Fipronil, although a newer generation insecticide, is also very persistent, and thats what makes it a good termiticide. But it should not be used for open area spraying because it can be picked up by foraging pollinators and returned to their hive to wipe out the entire colony. My understanding is that Fipronil should only be used in closed systems for structural applications. 

 

Imidacloprid is a neonicotinoid  systemic insecticide and should not be used for food producing plants. 

 

There are other botanical insecticides available, like neem seed oil extract (Azadirachtin), but these are better as repellent, for preventive timing and may not get much knock down for an active, advanced infestation. 

 

Common pyrethroids (synthetic chemical version of the old chrysanthemum flower extract, pyrethrum), like cypermethrin, while not organic program compatible and having their own downside of wiping out beneficial pest predators, they are considered least toxic for mammals, have relatively short residual (two or three weeks) and do get effective knock down for active infestations. But they are a contact and feedant spray for adults and don't go systemic to get to pests that are feeding internally. But that's what makes it more appropriate for a food plant with a skin covered fruit like bananas. You won't be eating it, unless you eat the banana flowers.