They are the family of insects containing most plant virus vectors (around 200 known) with the green peach aphid (Myzus persicae) being one of the most prevalent and indiscriminate carriers.

This is known as cyclical parthenogenesis and, in temperate regions, sexual reproduction occurs in autumn and results in the production of overwintering eggs, which hatch the following spring and initiate another cycle.

Thus, aphids show very complex and rapidly changing within-year dynamics, with each clone going through several generations during the vegetative season and being made up of many individuals, which can be widely scattered in space.

The cornicles have been variously interpreted as organs of excretion or for the production of honeydew, but their only confirmed function to date is that they produce fatty alarm pheromones when the insects are attacked by predators.

Aphids excrete a sugary liquid called honeydew, because the plant sap from which they feed contains excess carbohydrates relative to its low protein content.

To satisfy their protein needs, they absorb large amounts of sap and excrete the excess carbohydrates.

[6] The Aphid Species File[7] currently (2021) lists: On the UF / IFAS Featured Creatures Web site: