Across the corn belt depending on time of year | A longer rotation where corn is only grown a single year out of three results in usually only northern corn rootworm and its extended diapause. Western corn rootworm is seldom an issue with a rotation where corn is grown a single year. In this case, there is little pressure to build resistance to biocontrol nematodes and biocontrol nematodes will help with the suppression of wireworm attracted during the wheat year. Start growing corn back to back for 2 or 3 years and the pest becomes western corn rootworm and its ability to overcome a single management strategy.
My guess is that in the continuous corn - failing trait system where biocontrol nematodes are utilized to attack the trait resistant rootworm, rootworm will at some point develop nematode resistance. One mechanism for rootworm resistance to nematodes has already been identified in a 1989 paper. |
Biological Control of Rootworm - A link to a recent presentation
