Certified Arborist Practice Test

Insects with sucking mouthparts primarily seek plant fluids, which are rich in nutrients that are essential for their survival and reproduction. These mouthparts are specifically adapted for piercing plant tissues to reach the phloem or xylem, where these fluids are stored. The phloem contains sugars and other organic compounds that provide energy, while the xylem offers water and minerals.

This feeding behavior allows these insects to extract moisture and nutrients directly from the plant, which is crucial for their development and metabolic processes. The preference for plant fluids is a distinctive characteristic of many herbivorous insects, enabling them not only to feed but also to sometimes transmit diseases to plants through their feeding activities. Other choices, such as wood fibers or roots and soil, do not represent the primary sustenance needs of these insects, as they do not typically consume solid plant material or derive nutrition from the ground.