Across the corn belt depending on time of year | when we use a single management tool to control rootworm, the insect adapts or becomes resistant to the management tool.
For example:
When farmers adopted the widespread annual rotation of corn and soybeans, rootworm adapted and began laying eggs in soybeans known as the "rotation resistant" strain
When farmers used a single trait like YieldGard RW (Cry 3Bb1) or Herculex RW (Cry 34/35), Or Duracade ( eCry 3 + mCry3), rootworm adapted and became resistant. SmartStak and Qrome are just a mix of the previous trait toxins which were already burnt out by farmer's overuse.
RNAi is not expected to last very long based on laboratory studies.
Using Biocontrol Nematodes will be no different. If they are used alone, rootworm will also become resistant and my guess is about 5 years. Why? because rootworm has overcome all the other tools used as a single management tool in about 5 years. Rootworm is a tough and adaptable insect.
As you can see, we are trying to conserve this new independent mortality factor by only having it used with another management tool like a trait even if the trait is failing. BTW, soil insecticide only gives the farmer stand ability by protecting the base of the plant. It really does not kill many rootworms. In fact, a study in the 1970's showed there are more rootworm beetles emerging from a soil insecticide treated acre than an untreated acre due to protecting the roots at the plant base and therefore protecting the food supply for the RW larvae in the middle of the row.
For this reason, we are not making biocontrol nematodes available for non traited corn. |
Biocontrol nematodes - Rootworm - Persistent Biocontrol
