"Val Garden" wrote in message news:<MOD$020205.27132@rec.gardens.ecosystems>... > The way I understand it, the insect WILL NOT develop an immunity to the gmo > bt coded corn. > > Immunity requires survivors, so that the ability to survive the disease, > etc, would breed into the population. > > The gmo bt coded corn affects the critters on a genetic basis...and is 100 > percent effective with no infected critters surviving. > > Pretty neat, as long as nothing mutates further! > > Val >
Bt crops can and do have insects resistant to them. It was though
resistancy would take about a decade but the
diamond back moth became resistant within 3 years. There are other
lepodoptera species that are also resistant
to Bt crops (but I don't know about non egineered Bt resistance, if
that is happening yet).
This is why a buffer zomne of 1/3 the crop must be a non Bt variety in
hopes that insects would feed
on the non Bt corn and breed resistancy into their species.
Unfortunately until the EPA made a big
stink about buffer zones in 2000 only about 10% of the farmers growing
Bt crops actually planted one
Despite claims neither Bt nor any other insecticide will kill off 100%
of any insect species so there will
always be resistancy to insecticides.