sapfeeders

Sapfeeders are organisms that rely on plant sap as a primary food source. This group includes numerous insects such as aphids, whiteflies, scale insects, mealybugs, psyllids, and thrips, as well as some mites and certain beetles. Sap feeding is typically accomplished by piercing plant tissues with specialized mouthparts to access phloem or xylem sap.

Most sapfeeders use piercing-sucking mouthparts to insert stylets into vascular tissues. Phloem feeders tap into sugary phloem sap, which can create osmotic and nutritional challenges that are mitigated by osmoregulatory adaptations and specialized saliva. Xylem feeders, by contrast, consume relatively dilute water with minerals. Many sapfeeders produce honeydew, a sugary excretion that can attract ants and promote secondary sooty mold growth. Plant defenses, including thickened cell walls and defensive chemicals, have driven a diversity of morphological and behavioral adaptations among sapfeeders.

Ecologically, sapfeeders influence plant health and community interactions. They can weaken hosts through sustained feeding, reduce yields, and serve as vectors for plant pathogens such as viruses and phytoplasmas. Ants and other mutualists may protect sapfeeders from predators, helping to sustain large populations in some environments.

Representative groups and examples include: aphids (Aphidoidea), whiteflies (Aleyrodoidea), scale insects and mealybugs (Coccoidea), psyllids (Psylloidea), and cicadas (Cicadoidea). Sapfeeders also occur among mites and thrips. Management in agriculture and gardening often relies on integrated pest management, combining monitoring, biological control by natural enemies, cultural practices, and, when necessary, targeted chemical controls to minimize disturbances to beneficial organisms.