Hi JR,

     I believe I can answer your question about Bacillus Thuringensis (Bt) in corn with a parallel illustration from the world of potatoes. The same principles apply to the different subspecies of Bt used to target different insects. I believe I read there are 800 different subspecies of the bacteria Bt growing in forest soils that have been identified. Some subspecies have been commercialized. Bti (israeli) controls mosquitos. Btk (kurstaki) controls lepidotera (larvae of moth and butterfly) and is widely used by organic farmers to control crop pests. This Bt is very important to organic farmers and is commonly used.

     In the mid-1990s Monsanto introduced to the market their "New Leaf" potatoes which were gene-spliced with Btt, the Bt subspecies (Bt tenebrionsis) effective at controlling Colorado Potato Beetle. For many years, when CPB pressure was high, organic farmers would spray Btt on the potato plants in the late afternoon. CPB would feed on the potato leaves and overnight ingest a lethal dose of the Btt bacterial stomach toxin which would immediately paralyze their gut and lead to CPB death within a day or two. As soon as the sun's rays got to shining the next morning the Btt would begin to break down rather rapidly and would be gone within maybe 48 hours of application.

     Normally, depending on CPB pressure and mean temperatures, we would spray Btt a second time, again in the late afternoon about seven days later in order to control larva that had hatched subsequent to our first Btt application. Again, kill took place overnight and again the Btt began to break down in the presence of sunlight that next morning. Importantly, since insect resistance to a toxin develops in direct correlation to length of exposure/interaction (more interaction equals faster development of resistance) we were grateful that Btt did its control job quickly and then disappeared.
     A typical potato variety grows for 120 days. In our organic potato field, CPB typically interacted with Btt for just 96 hours or 4 days out of the 120 days or 3.3% of the season. Monsanto had gene-spliced the Btt toxin into their "New Leaf" potatoes to control CPB.  That is, every cell of those "New Leaf" potato plants, including the tubers which people eat, expressed that bacterial toxin. Over the short term the "New Leafs" controlled CPB. However, it is important to understand that the "New Leaf" version of that 120 day potato variety expressed the Btt for all 120 days.  That means CPB interaction with transgenic Btt was all 120 days or 100% of the season.
     Resistance absolutely was predictable.  In fact, in April 1996 as a stakeholder I attended a USDA conference on Transgenic Bt Resistance held in Bethesda MD. The nation's leading entomologists were also in attendance. Their clear consensus was that transgenic Bt resistance, whether in potato ("New Leafs" were rejected by the market and removed from production around 2001), corn or cotton, was not a matter of whether, but a matter of when. So transgenic Bt resistence was predicted fifteen years ago. No one should claim surprise with new reports of transgenic Bt resistance.

     Once a population of insects becomes resistant to a material such as Bt, there is no going back: the material will never again work as a control. It is ruined for all.

     It seems that justice would require culpability for an entity that misuses a treasure taken from the commons, like Bt, and ruins it.  And most especially after they were warned at the start that their technology would result in this loss.

Jim