How can one identify if aphids have been parasitized?

The identification of parasitized aphids is primarily indicated by changes in their physical appearance. When aphids have been parasitized, they typically undergo a transformation where they change color and become mummified. The mummified appearance results from the development of the parasitoid inside the aphid, which eventually leads to the death of the aphid while the parasitoid has completed its life cycle. This process often involves the loss of elasticity in the aphid’s body, causing it to shrivel, and they generally take on a tan or brown color after being parasitized.

The other options do not accurately represent the signs of parasitism in aphids. For example, while aphids may become larger or greener under certain conditions, this is not a definitive sign of parasitism. Similarly, producing fewer offspring may occur for various environmental or health-related reasons and is not a direct indicator of parasitism. The tendency for aphids to fly away is influenced by factors such as stress or overcrowding, rather than being a specific sign that they have been parasitized.