Various life stages of tulip bulb aphid, Dysaphis tulipae, on a leaf.

A close up of a population of insects on a green leaf. Various sizes of lime-green aphids with teardrop shaped abdomens are present. One parasitized aphid is brown and the abdomen is round. Credit: Whitney Cranshaw, Colorado State University, Bugwood.org<br />Licensed under a <a href="https://creativecommons.org/licenses/by/3.0/us/">Creative Commons Attribution 3.0 License</a>
Credit: Whitney Cranshaw, Colorado State University, Bugwood.org
Licensed under a Creative Commons Attribution 3.0 License