red palm weevil

[Ferry]

These emblematic palms of the municipality of "Hyères les palmiers" (France) were condemned to death by all the national Plant Protection Authorities in Europe and by most of the red palm weevil experts.

It has now been well established that infested palms can be cured by a technique that we have called mechanical sanitation. It has also been well established that early detection is quite feasible and constitutes the core to succeed the eradication of the RPW.

Contrary to what has been said, written and repeated so many times, even by so called experts, early symptoms of infestation appear inevitably and rapidly on Phoenix canariensis the main target of the RPW and probably the R. palmarum in our gardens. When the origin of these symptoms has been explained, everybody is able to detect most of them from ground.

Closed to infested palms or traps that have captured weevils, opening of inspection windows or even cutting all the outer and middle crowns fronds is absolutely indispensable. In these places we have to track the RPW to avoid its dispersal. If we actively look for the earliest symptoms, we can eradicate quickly the pest because we prevent any dispersal.

Trimming the palms does not constitute at all a danger. It does not increase or facilitate infestation. It can just play a role in the selection by the females of the palms to infest. It is, as largely demonstrated, an indispensable activity to detect early infested palms. Presently, more than 200 professionals have been trained in France to apply all the techniques of an integrated eradication strategy.

Michel Ferry

INRA France

Email: ferry.palm@gmail.com

[Gonzer]

Michael, if I may add a footnote; what Southern Californians need to worry about now/also is the progress that the South American Palm Weevil has shown since detection in San Ysidro. The worst is that the individuals trapped in areas close by SY are following a route dictated by Interstate 5 heading north. This information was presented at a PAPA seminar in Escondido on Sept. 20. While many folks confuse Fusarium Wilt with RPW infestations the characteristic damage (seen from the ground) done by both are almost completely opposite of one another. Fusarium starts with older leaves and RPW affects the newer.

[LJG]

Hey Gonzer. I am not sure this is so true. Fusarium infected trees can have leaves start showing in newer leaves too. I have witnessed this myself in my own trees. I think the big difference is the one-sided dieback that is Fusarium. I was not at this meeting but did they say the weevil damage can also show this?

[Gonzer]

Len, I should clarify...the slides that were shown for comparison purposes showed Fusarium mainly affecting the lower crown while the RPW infestations showed marked damage only on the newest/new fronds, often in the form of grasshopper-like damage. Since the majority of the slides showed significant crown disfigurment from the weevils the only consensus that can be drawn is the this: the adult lays its clutch of eggs in the only area accessible...straight down the crown since the adult does not have the capabilty to bore into the trunk. Now this isn't to say that perhaps grubs can somehow find themselves outside looking in and therefore bore into the lower part of the trunk inflicting damage that is reminiscent of Fusarium. Make sense?

[Cristóbal]

Michael, if I may add a footnote; what Southern Californians need to worry about now/also is the progress that the South American Palm Weevil has shown since detection in San Ysidro. The worst is that the individuals trapped in areas close by SY are following a route dictated by Interstate 5 heading north. This information was presented at a PAPA seminar in Escondido on Sept. 20. While many folks confuse Fusarium Wilt with RPW infestations the characteristic damage (seen from the ground) done by both are almost completely opposite of one another. Fusarium starts with older leaves and RPW affects the newer.

I am very sorry learn rhyncophorus palmarum is now in San Ysidro California but to me this is not some surprise.

In december of the last year i find this weevil for the first time in the history of the state of Baja California, in Tijuana, very close to the border only 100 meters from the street where the cars go to San Ysidro California. This palm and weevil i find when i see here one palm that i think may be have the red weevil.

The 2 weevils do the same thing to the palms.

The specialists Mark and Christine Hoddle of University of California, they come to verifey investigate this and they take some weevils back to USA, and they find it is the brother of the red palm weevil.

You can read about this and see the many fotos of this weevil and the investigation of Mark and Christine Hoddle here pages 11 - 14.

Red Palm Weevils California

When i find this weevil we hope it is only here in Tijuana in one palm. Now i learn it is in San Ysidro by the freeways ! What i think is they go from the first palm i find in Tijuana on some cars going to USA, they go to San Ysidro and it is for this you find it now by the freeways there.

When you see what the weevil does to the palms, and very fast, you feel sick.

For me the question now is how to eliminate or control this weevil in both California and Baja California ?

And what happen now with the red weevil they find in Laguna Beach much more north of here ?

Edited September 22, 2011 by Cristóbal

[Kostas]

The damage from Rynchophorus ferrugineus appears visibly when their tunnel passes through the spear. The new leaf will have a hole(or holes) bored through many leaflets or,if the tunnel is very wide,the whole distal end of those leaflets may be missing,appearing like you cut through some leaflets diagonally with a scissor till you reached the rachis and stopped there. It doesnt cause necrosis till a very advanced stage where the middle crown leaf bases become so tunneled that they fall off along with the leafs they were supporting. The oldest leaf bases hang on the longest along with some stunted new leafs if the meristem is not damaged yet.

Here in Europe,we have lots of Rhynchophorus ferrugineus in many areas and for me,monthly nematode + Biorend R(Chitosan) applications on the crown,provide adequate protection. When i for some reason,delay an application,i start seeing sign of Rhynchophorus damage on my palms and Trachycarpus fortunei are the first to show holes on the newest leaf. The good thing is,they seem to disappear with the first subsequent application as i see no further holes

[Gonzer]

What is frightening is the fact that we, as plam lovers, have to suffer through the threat of so many exotic pests year in and year out. We are just a small facet of the horticultural community. How many collectors/growers of say cactus, orchids, evergreen trees, annuals, etc., are going through the same pains we are? I'm sure none of us save a few are aware of the myriad of pests that threaten so many families in the plant kingdom. Just a reminder that although the customs procedures are long and tedious they serve a purpose.

[Ferry]

Regarding R. palmarum, its infestation process on Phoenix canariensis is very similar to RPW one’s. Consequently, the same integrated strategy, based principally on early detection and immediate sanitation, can be adopted to eradicate this pest.

Various other early symptoms than holes or the famous V cuts that are not always present are available to detect the pest. But, once more, earliest symptoms, not visible from the ground and without cutting leaves to reach the bases of the inner leaves, must be actively looked for. In infested areas (less say 200 meters around an infested palm or a trap that has captured), we must not wait till the growth of the fronds is enough to detect visible ground symptoms (too much key months lost to stop pest dispersal). We must detect them earlier to prevent any pest dispersal or stop it as soon as possible. If we do so, we can eradicate very quickly these deadly pests.

To succeed quickly eradication (if eradication is not conceived to succeed quickly it will fail), monitoring traps constitute a poorly efficient make-shift compared with active awareness, information and training on early detection and immediate sanitation. The radio of attraction of a trap does not exceed few hundred meters in the best conditions and attraction is different from capture: the best trap will not capture more than 50% of the flying weevils (at least for R. ferrugineus). When traps will start to capture, visible symptoms will be detectable long time before and weevils dispersal from the initial infested palm will have also started long time before. Furthermore, when a trap has captured, an important and immediate effort of awareness, information, training and active earliest symptoms research (with palms trimming) will have to be implemented to make this information useful. So it is much more efficient to do this effort at the beginning.

Regarding FO fsp canariensis or albedinis, there are a lot of evident differences between the symptoms created by these fungi and the ones resulting of RPW or R. palmarum infestation. The symptoms created by the two Rhynchophorus are physical and mechanical consequences of the larvae activities (previous to the symptoms apparition). This physical origin creates different types of symptoms very different from the discoloration (not always one side) and dryness created by the vascular fungus progressing in the fronds.

Best regards.

Michel Ferry

INRA

Email: ferry.palm@gmail.com

[Nigel]

Are you sure that R palmatum is causing equal problems to the RPW ?

I find this hard to believe.

There are many large Phoenix here in Florianopolis some more than 100 years old, and they have lived amongst R palmatum without problem their whole lives.

R palmatum can be a problem, but it is always in stressed palms that have been transplanted and suffered severe trimming. They attack all palms equally when severely stressed by transplant and trimmed.

This is not the same behaviour as RPW which attacks healthy strong palms.

[Ferry]

Are you sure that it is R. palmarum? Till now, in the scientific litterature about R. palmarum dispersion, this specie has not been not signaled in Santa Catarina state. I think also that the question is based what are the available palms to choose for the weevil. RPW has left the Phoenix dactylifera when it has found the P. canariensis in southern europe. Now, that in some places the number of P. canariensis has been greatly reduced, it comes back to the P. dactylifera as well to other palm species.

[LJG]

Len, I should clarify...the slides that were shown for comparison purposes showed Fusarium mainly affecting the lower crown while the RPW infestations showed marked damage only on the newest/new fronds, often in the form of grasshopper-like damage. Since the majority of the slides showed significant crown disfigurment from the weevils the only consensus that can be drawn is the this: the adult lays its clutch of eggs in the only area accessible...straight down the crown since the adult does not have the capabilty to bore into the trunk. Now this isn't to say that perhaps grubs can somehow find themselves outside looking in and therefore bore into the lower part of the trunk inflicting damage that is reminiscent of Fusarium. Make sense?

Ok, thanks. Makes sense.