Pleased to announce I was invited to participate in a nationwide analysis of corn earworm trends. This new study from Dr. Lawton (NC State) et al. takes a look at decades-long trapping and soil temperature data to provide some insight into overwintering potential of H. zea, and how we might use models to predict pest abundance. Highlights from the article:

  • H. zea population dynamics are hierarchically structured with continental-level effects that are partitioned into three geographic zones.
  • A 40-year averaged overwintering suitability map was constructed based on remotely sensed soil temperature and it projected the transitional zone to be largest in area; Western Oregon fluctuated between the transitional zone and the southern range, depending on year.
  • Because H. zea is a highly migratory pest, predicting when populations accumulate in one region can inform synchronous or lagged population development in other regions.
  • It is generally accepted that H. zea does not overwinter above 40°N latitude, but this new analysis suggests that range is more fluid and depends instead on soil temperatures.
  • Greater overwintering survival may expand the range of a serious insect pest.
  • The authors acknowledge that regional within-season factors (precipitation, IPM strategies, agronomic practices, etc.) also influence population dynamics.

Lawton, D., et al. (2022). “Pest population dynamics are related to a continental overwintering gradient.” Proceedings of the National Academy of Sciences 119(37): DOI: 10.1073/pnas.2203230119

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