CDFA Pest Prevention Plant Regulation Practice Exam

What stage of the Colorado potato beetle is responsible for the most damage?

1. Egg stage

2. Larval stage

3. Pupal stage

4. Adult stage

The correct answer is: Adult stage

The life stage of the Colorado potato beetle that is responsible for the most damage is the larval stage. During this phase, the beetles feed voraciously on the foliage of potato plants and can cause significant defoliation within a short period. Larvae have a high food intake and can consume large amounts of leaf material, which can severely impact the plant's health and yield. While adults can also cause damage by feeding on the leaves, their impact is generally less compared to the larval stage. The adults lay eggs on the undersides of leaves, and when these eggs hatch, the larvae emerge ready to consume as much plant material as possible. The pupal stage does not feed at all, as it is a transitional stage where the beetle undergoes metamorphosis, thus it does not contribute to damage during this time. Therefore, the larval stage is clearly the most damaging to potato crops.