Pests becoming resistant to Bt GMO crops

[Appalachia]

Pests becoming resistant to GMO crops due to inadequate non-GMO refuges planted near the main GMO crop.



"More pest species are becoming resistant to the most popular type of genetically-modified, insect-repellent crops, but not in areas where farmers follow expert advice, a study said on Monday.

The paper delves into a key aspect of so-called Bt corn and cotton — plants that carry a gene to make them exude a bacterium called Bacillus thuringiensis, which is toxic to insects.

Publishing in the journal Nature Biotechnology, US and French researchers analysed the findings of 77 studies from eight countries on five continents that reported on data from field monitors.

Of 13 major pest species examined, five were resistant by 2011, compared with only one in 2005, they found. The benchmark was resistance among more than 50 percent of insects in a location.

Of the five species, three were cotton pests and two were corn pests.

Three of the five cases of resistance were in the United States, which accounts for roughly half of Bt crop plantings, while the others were in South Africa and India.

The authors said they picked up a case of early resistance, with less than 50 percent of insects, in yet another US cotton pest.

And there were “early warning” signs (one percent resistance or less) from four other cotton or corn pests in China, the United States and the Philippines.

The scientists found big differences in the speed at which Bt resistance developed.

In one case, it took just two years for the first signs to emerge; in others, the Bt crops remained as effective in 2011 as they were 15 years earlier.

What made the difference was whether farmers set aside sufficient “refuges” of land for non-BT crops, said the study’s authors."


http://www.rawstory.com/rs/2013/06/1...odified-crops/

[Steve in PA]

"carry a gene to make them exude a bacterium called Bacillus thuringiensis"

That made the entire rest of the article not worth reading. A bacterium is a living thing, a bacteria. That is like saying corn can make monkeys. It is the toxin created by that bacterium that is lethal to some insects.

...And the basis of my concern for Bt Corn since I don't know what long term repeated exposure to that chemical does to my body.

[tinknal]

Funny this should come up. I've heard of this before and just today I was wondering why the seed companies don't just include a percentage of non bt seed in the bag.

[Appalachia]

Originally Posted by Steve in PA

"carry a gene to make them exude a bacterium called Bacillus thuringiensis"

That made the entire rest of the article not worth reading. A bacterium is a living thing, a bacteria. That is like saying corn can make monkeys. It is the toxin created by that bacterium that is lethal to some insects.

...And the basis of my concern for Bt Corn since I don't know what long term repeated exposure to that chemical does to my body.

Haha I missed that. Poor wording for sure.

[Appalachia]

Originally Posted by tinknal

Funny this should come up. I've heard of this before and just today I was wondering why the seed companies don't just include a percentage of non bt seed in the bag.

That's a good idea. I wonder if the "island" of non-GMO is needed so the pests breed there instead of being mixed throughout the GMO area.

[JMD_KS]

Nature is smarter than man.

[rambler]

Originally Posted by tinknal

Funny this should come up. I've heard of this before and just today I was wondering why the seed companies don't just include a percentage of non bt seed in the bag.

Search for 'refuge in the bag' and you will find that is the new way, perhaps on its third year, of doing things.

It is not as easy as it sounds, as there are problems with doing it that way. The point of the refuge is that bugs survive in the refuge area, unaffected by the bT plants. If you mix it all on the same bag, then the bugs will all get exposed to some bT corn, as the plants are intermingled.

But, they've worked out a way to do it.

Other problem is, not 5-10% of your field is a target for bugs, and how do you deal with that? Other way, with a refuge, you had a block of a field you could treat with regular pesticide.

Paul

[o&itw]

Originally Posted by Steve in PA

"carry a gene to make them exude a bacterium called Bacillus thuringiensis"

That made the entire rest of the article not worth reading. A bacterium is a living thing, a bacteria. That is like saying corn can make monkeys. It is the toxin created by that bacterium that is lethal to some insects.

...And the basis of my concern for Bt Corn since I don't know what long term repeated exposure to that chemical does to my body.

I am no fan of GMO crops. And I don't know how they work.

BUT Bacillus thuringiensis does not exude toxins to kill pests. It invades the (Worms/ laval stages of insects) body and consumes it host. I used the bacteria 30 years ago on my cabbage. It was a great organic pesticide for certain things like cabbage worms.

[highlands]

Works in several ways.

Bacillus thuringiensis (or Bt) is a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide; alternatively, the Cry toxin may be extracted and used as a pesticide. B. thuringiensis also occurs naturally in the gut of caterpillars of various types of moths and butterflies, as well on leaf surfaces, aquatic environments, animal feces, insect rich environments, flour mills and grain storage facilities.[1][2]During sporulation, many Bt strains produce crystal proteins (proteinaceous inclusions), called δ-endotoxins, that have insecticidal action. This has led to their use as insecticides, and more recently to genetically modified crops using Bt genes. Many crystal-producing Bt strains, though, do not have insecticidal properties.

http://en.wikipedia.org/wiki/Bacillus_thuringiensis

[where I want to]

To monocrop anything on a large scale is to create a billion opportunities to create a pest that can use that crop. All it's competitors will be eliminated by built in insecticides so it has an opportunity to jump from a unique mutation to the dominant organism.
Then BT becomes useless. Something that can knock down a serious but occasional population surge is lost.
This was and is going to be the way back to having nothing effective to use when it is desperate for the sake of a few years of improved yields.
If it hasn't happened yet, it will. It is inevitable.

[AngieM2]

So, this is saying that a fully GMO field planted GMO year after year will gradually have the bugs coming back resistant to it, so it won't be good for that anymore. But, to make it stay bug resistant there has to be a bug offering field nearby for them to feast on (cause it's easier maybe?)

Am I reading that right?

[simi-steading]

We really should stop messing with mother nature..

[rambler]

Originally Posted by AngieM2

So, this is saying that a fully GMO field planted GMO year after year will gradually have the bugs coming back resistant to it, so it won't be good for that anymore. But, to make it stay bug resistant there has to be a bug offering field nearby for them to feast on (cause it's easier maybe?)

Am I reading that right?

Correct.

The bug gmo products have always had a 'refuge' requirement to try to keep resistance from forming.

I understand in cotton areas the refuge area might be 50% of the field. Where I am, it was typically 20% of the field needs to be a non-bT type. This needs to be either a rectangular portion of the field in one block; or it needs to be a certain number of rows of your planter (like 2 out of 8 rows) that make strips of at least 4 rows of non-bT corn.

Newer types now have different requirements, and the last couple of years they have 'refuge in a bag' where the seeds, including a non-bT type, are all in the same bag. I believe these types of seed have 2 different bT types of GMO, as well as 5% non-bT seeds all in one bag, but don't take that as gospel.

All this is based on some science, so as to keep bT resistance from developing.

Of course 2 things happen, nature figures out a way, and people cheat a bit.

And that leads to resistance on any sort of system. Even using vinegar as weed control, weeds will move into your garden that like acidic soils....

It is the constant back and forth between us humans and nature. It happens to any system, the old ones, the newest ones.

It is how life goes.

I'm disappointed that the resistance happens, but it is inevitable, to anything we do. Bacteria drugs, weed sprays, when dad and I were using only plow, disk, harrow, cultivator, and hoe there were weed types that moved in that were able to survive that and thrive. Basically, it was resistance to our ways of dealing with weeds.....

Paul

[rambler]

I should address your question a little better perhaps, Angie.

This refuge idea only applies to bug traits, not weed traited gmo crops.

The theory behind it is some bugs will eat and grow on the refuge portion of the field, so that they will grow and reproduce and will mate with any very very few bugs that have survived the bT crop - those one in a billion that are resistant.

Their offspring would not be tolerant of the bT crop, and so resistance would not happen, or at least not rapidly.

That is why bigger rectangles of non-bT crop area are needed, so that bugs can live and grow without being exposed to the bT-crop.

This makes some scientific sense.

On the other hand, from the farmers point of view, one is creating a breeding grounds for the bugs to remain, year after year, and is kinda dumb. Why not kill all the bugs you can, and be rid of them... As well, you are sacrificing 20% of your crops to bugs - is that something anyone really wants to do?

And so, some did not/ do not follow the rules on this. They are wrong, but perhaps one can see where they come from.....

The bugs don't know a difference in regular corn or bT corn, its all the same to them. They have to eat some of the green plant to ingest the bT and die, so one will still see a little insect damage on bT crops. There is not attraction or repulsion involved.

For disclosure, I have used a very few bags of bT corn over the past 4 years, less than 10% of what I plant. In my case I do not see a big insect problem on my corn in my location, even planting corn on corn, so don't want to pay the extra expense of it. Obviously, I don't have problems with keeping a refuge, as most of my farm is.

Bug insecticides for corn and cotton are really bad things, pretty dangerous, way more than the weed killers we use. So for those areas that need bug control on their crops, the bT was sure a safer option for all of us, in my opinion. It is unfortunate resistance happens, as without bT working, we will return to the strong insecticides.

Paul

[AngieM2]

Thanks Paul/Ramber

doesn't seem right. planting areas for the bugs, or having them go to a less 'modern' field that is near a 'modern' field.

Just seems rather stupid as in the long run, the bugs are getting fed and what is the bottom line cost to have a bug buffet at one location and not just treat the field that is not bt corn/or cotton as it would have been in the past before this bt stuff?

What percentage of increase in overall yield is seen doing this dual planting?

(and I can see a great Saturday afternoon grade B sci - fi bug horror movie out of this)

[Bearfootfarm]

So, this is saying that a fully GMO field planted GMO year after year will gradually have the bugs coming back resistant to it, so it won't be good for that anymore. But, to make it stay bug resistant there has to be a bug offering field nearby for them to feast on (cause it's easier maybe?)

Am I reading that right

Look up "Refugia" and it explains the concept of providing areas for pests to NOT be exposed to pesticides, and don't overlook the first line of the OP's quoted article:

"More pest species are becoming resistant to the most popular type of genetically-modified, insect-repellent crops, but not in areas where farmers follow expert advice, a study said on Monday.

Resistance is NOT a problem if directions are followed

[rambler]

You may spray the field with insecticide to control the bugs in the refuge area, however you are supposed to spay the whole field if you spray, not just the refuge area. So you lose any cost savings.

As you say, it seems odd to the growers, but it was designed to keep the resistance issue from happening, and makes sense scientifically. Just sorta defeats the point of it all.

Any more, with the price of crops, farmers are going towards protecting their crops in multiple ways, both gmo and the older sprays, to keep Mother Nature beat back.

A decade or two, and we might all be spraying vinegar as well!

Paul

[AngieM2]

thank you BFF. I got that now. Still think it's silly to give bugs sacrifical offering areas, but that's just what seems silly to me.

[where I want to]

Originally Posted by rambler

Their offspring would not be tolerant of the bT crop, and so resistance would not happen, or at least not rapidly.

Paul

And there is the rub. For one thing, no one knows how a BT resistant gene will express itself. Maybe it will have a dominant effect on the mass of "cultivated" bugs such that in a generation or two, that gene will be lurking in all bugs anyway. A BT reisistant bug may have a more vigorous system and will outbreed the not-resistant.
Genes are not like a solution where you can dilute it out of existence. All organizisms have genes that are apparently left over from earlier generations and don't seem to have a purpose currently but spring to life in the right circumstances.
And even if this was successful, it only postpones the resistence.

[I_don't_know]

God made the mountains
God made the sky
God made the people
God knows why?
He fixed up the planet as best as he could
And in come the people and muck it up good

From “Paint Your Wagons”, Clint Eastwood and Lee Marvin in a musical would believe!