Certified Arborist Practice Test

Scale insects primarily feed on phloem tissue, which is responsible for the transport of nutrients, particularly sugars, throughout the plant. These insects use their specialized mouthparts to pierce the plant’s exterior and access the phloem, drawing out the nutrient-rich fluids. This feeding strategy not only provides them with essential sustenance but also has significant implications for the health of the plant.

Feeding on phloem can lead to various issues, such as reduced plant vigor, stunted growth, and even plant death if the infestation is severe. In addition, this feeding can lead to the secretion of honeydew, which can promote the growth of sooty mold, further impacting the plant’s ability to photosynthesize effectively.

Understanding that scale insects target phloem is crucial for arborists and those dealing with pest management, as it highlights the importance of monitoring for these pests and applying appropriate control measures to mitigate their impact on trees and shrubs.