Controlling Giant Salvinia

[jpcajun]

Information from the meeting on August 22nd:

Giant salvinia in southwest Louisiana should be under control in a few years. In the meantime landowners can combat the invasive aquatic weed with herbicides, according to an LSU AgCenter weed specialist.

Dearl Sanders (AgCenter Weed Specialist) told landowners that salvinia came to Louisiana in 1999, imported by commercial water garden companies. He said the plant also is a problem in Australia, Indonesia and New Zealand.

“It is the poster child of invasive species,” he said.

The floating plant is closely related to Boston ferns, and it reproduces by spores instead of seeds. He said one plant can multiply until it covers 40 square miles of water in one year.

“It has the fastest growth rate of any plant on the planet,” he said.

Once waterways are covered with the weed, fish and other aquatic creatures either die or leave the area. Other vegetation, blocked from sunlight, inevitably dies, leaving an underwater desert, Sanders said.

He said controlling 90 percent of a weed is considered a success, but controlling 90 percent of a salvinia infestation is ineffective. “Within 30 days you are back to 100 percent coverage again.”

He said the best chemical is Diquat, but it is expensive. Glyphosate works well at high concentrations, he said, but it is more effective when mixed with a small amount of Diquat.

The herbicide combination should be used with a surfactant to get coverage on the plant’s hairy leaves. Dishwashing soap is not an acceptable surfactant because it interferes with the herbicides’ chemistry, so commercial surfactants should be used, he said.

He said spraying can be accomplished with a high-pressure sprayer or by aircraft. He said spraying three times will be required within a few weeks.

Plants that have turned brown but are still floating will be able to reproduce. “The only time you know it’s dead is when you can’t see it.”

Sanders said salvinia weevils, raised at the LSU AgCenter’s Bob R. Jones-Idlewild Research Station near Clinton, have been released across southwest Louisiana, and they should solve the salvinia problem within three years. He said the insect was used in the Terrebonne Basin, and the weed was eradicated in large areas.

The insect should work well in southwest Louisiana, too, he said, although it’s unknown if insecticides used in adjacent crop production may affect the salvinia weevil.

He said once the salvinia weevils have eaten salvinia, they no longer have food, and they crawl on land where they fall prey to fire ants.

Saltwater kills salvinia, he said, and that’s what killed an outbreak in the Prien Lake area at Lake Charles.

He said the weevils are being used in north Louisiana also, but the colder winters there tend to kill the insect population.

I know a lot of you deal with this in your marshes and other waterways so thought this would help some of you out!

[Matt G]

Thanks for the summary!

[BGcoreg]

I wanted to revive this thread and try to bring some attention to this topic. I've been hunting in little chenier area since 2006 and maybe 2-3 years ago I met a fella on here that hunted several miles north of us. I remember him saying that they had salvinia real bad and that it would make it to us in a matter of time. I thought surely not because our place has very tight canals and there are hardly any large canals that lead to our place so I figured the salvinia would never be able to travel. Well as you prolly guessed the salvinia has now made it to our marsh. I noticed it in 2014 in some nearby canals and this year noticed it in our canals. They are small patches but I've seen what it can do. Anyways......
I recently tried to contact Mr sanders who was over the weevil project at LSU as I understood, and discovered he has retired and the project/research is now in Mr Diaz's hands. I just got off the phone with him and trying to make conversation he all of a sudden asks "do you need weevils"? Well, mr Diaz you read my mind. Sadly, they are only supplying that state lands with the weevils because they do not have enough weevils to supply individuals like myself. He said they are currently trying to work something out to where individuals can come get them though.
Meantime, chemicals is obviously an option but they are expensive. Diaz suggested I collect salvinia from sites that the weevils have been introduced to and move the salvinia and weevils to our site. He is supposed to be sending me gps locations where the weevils have been introduced and go from there.

What would really be nice is if you wanna fellas had an inside hookup to wild life and fisheries to hook me up with some weevils!


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[swamp snorkler]

Weevil Life

[swglenn]

I saw some in the Burns this week. I haven't seen any in Lacassine but that doesn't mean it isn't there.

[ckinchen]

Ended one of my duck leases. Great property in a nice "ducky" location. The entire marsh was covered in it. I spent thousands every year and just couldn't spend the time out there it would really take to kill it.

[BGcoreg]

Originally Posted by swglenn

I saw some in the Burns this week. I haven't seen any in Lacassine but that doesn't mean it isn't there.

I just read another article where they are trying to have weevil rearing ponds at Lacassine NWR to be able to supply individuals and whoever wants them. It was written in Jan of 15' so not sure where they are now on the project. Doesn't seem like Miami corps cares as long as they get there lease money

[Duck Butter]

There are two types of salvinia - common and giant. When you receive the weevils, you don't just get a bag of weevils, you get a bunch of salvinia that has weevils in them. You can barely see the weevils. If you have one type of salvinia, make sure you do not get weevils from the other salvinia. They are the same weevils, but you dont want to be adding a new invasive in there. So if you have common salvinia, dont add in giant salvinia to your problems

Salvinia is the devil

[BGcoreg]

Originally Posted by Duck Butter

There are two types of salvinia - common and giant. When you receive the weevils, you don't just get a bag of weevils, you get a bunch of salvinia that has weevils in them. You can barely see the weevils. If you have one type of salvinia, make sure you do not get weevils from the other salvinia. They are the same weevils, but you dont want to be adding a new invasive in there. So if you have common salvinia, dont add in giant salvinia to your problems



Salvinia is the devil

Correcto

[Lake Chuck Duck]

Delta Waterfowl was sponsoring a big project with state matched funds to grow and distribute Weevils. The state matched money is being cut so the project is at a hold right now.

[meaux fishing]

Originally Posted by ckinchen

Ended one of my duck leases. Great property in a nice "ducky" location. The entire marsh was covered in it. I spent thousands every year and just couldn't spend the time out there it would really take to kill it.

That place was a mess. Good location though

[BGcoreg]

Anyone ever made there own Lillie booms? Like oil booms?

My goal would be just to block off salvinia from getting into canals that are anywhere from 4-10ft wide..
So I was thinking of 4-6"PVC pipe capped on the ends and putting it to where it can float up and down but not move from its position. Like a floating dock.
And a boat could still drive over it

[biggun]

All U need is one white heron to have the seeds on their legs. It grows like wildfire. 2-4 D and par-qote (spelling) with COMMERICAL surfactant will kill it..

[B-Stealth]

Originally Posted by biggun

All U need is one white heron to have the seeds on their legs. It grows like wildfire. 2-4 D and par-qote (spelling) with COMMERICAL surfactant will kill it..

Dang your right and that sucks, I knew how landlocked ponds were "stocked"' just didn't think about the salvania as well. We're currently salvanian free near an area with salvania. Thx for the chemical advice.

[BGcoreg]

I spoke with several different folks the past few days. Talked with a fella today , Kevin Savoie , super nice guy.. He says they had a nursery around Houma- new Iberia area and the land owner decided he did not want to continue with the project. Basically, they need a landowner or landowners to put up property that has water access to pump and levees to use. He said I haven't been the first to call and ask for weevils.
He is surprised that the bigger companies like sweet lake land and oil, or Miami haven't headed up any of these projects.
I told him to keep my # and if there were any updates to let me know. He thinks forming some kind of organization or private land owners will end up being the solution. Until then. A hurricane will be the only solution and nobody wants that ( that I know of)

[BGcoreg]

Oh and I'm also thinking about attempting to make a map of where salvinia currently is.. Mainly just for Cameron parish but might as well expand it because I'm sure others are having problems with it. I have access to some great computer software for maps and what not and is something I enjoy doing. Once I figure out how I wanna set it up I'll try and update . For example I'd like to have an aerial map that has highlight or colored canals , ponds, or any areas that have salvinia with them.