Which of the following is a common pest found in greenhouses?

Aphids are a common pest found in greenhouses due to their ability to reproduce rapidly and thrive in warm, humid environments. These small, soft-bodied insects feed on the sap of plants, which can weaken the plants and lead to stunted growth, yellowing leaves, and potentially transmitting plant viruses. They are particularly problematic in greenhouse settings where plants are closely spaced, creating ideal conditions for their population to grow unchecked.

On the other hand, while ladybugs are beneficial insects that help control aphid populations, earthworms typically inhabit soil and are more associated with soil health rather than being greenhouse pests. Various types of beetles can occur in greenhouses, but not all beetles are general pests or as prevalent as aphids. Therefore, aphids are recognized as one of the most common and problematic pests encountered in greenhouse operations.