What stage do European corn borers overwinter in Missouri?

European corn borers overwinter in the pupal stage. During this stage, the larvae have completed their growth and transformation into pupae, which are a more resilient form that allows them to survive harsh winter conditions. The pupal stage is critical because it provides the necessary protection needed to withstand cold temperatures until spring.

In Missouri, when the weather warms up in the spring, these pupae will emerge as adult moths, ready to complete their life cycle by laying eggs on corn plants and other host vegetation. This overwintering strategy is advantageous because it allows for an early start in the growing season, ensuring that they can take advantage of favorable conditions for growth and reproduction.

Understanding the overwintering stage of the European corn borer is vital for managing this pest effectively, as it helps in predicting their life cycle and potential impact on crops. Knowing that they overwinter in the pupae helps in timing control measures for when they are most vulnerable after emergence in the spring.