CDFA Pest Prevention Plant Regulation Practice Exam

During which stage does the Colorado potato beetle overwinter?

1. Egg stage

2. Laval stage

3. Pupal stage

4. Adult stage

The correct answer is: Adult stage

The overwintering stage of the Colorado potato beetle occurs during the adult stage. Adults are able to survive cold winter temperatures by burrowing into the soil or finding shelter in debris. This characteristic allows them to endure adverse weather conditions and emerge in the spring when temperatures rise and food sources are available. In contrast, the other stages—egg, larval, and pupal—are less capable of surviving through winter conditions. Eggs, laid in clusters, are vulnerable to environmental factors and do not survive winter. Larvae, which are the juvenile stage, rely on having a host plant to feed on and are also susceptible to harsh weather. The pupal stage occurs after the larval stage, but it is a transformation phase that cannot endure winter conditions independently outside of the protective environment provided by the parent beetle. Therefore, the adult stage is the only phase of the Colorado potato beetle that has adapted mechanisms for surviving winter months.