Bean aphid
Aphis fabae
35 host plants
Last updated
Dense colonies of black bean aphids cluster on stem tips, flower buds, and leaf undersides of beans, peas, and other legumes starting in late spring. You will notice curled, distorted new growth and sticky honeydew deposits that attract ants. Sooty mold develops on honeydew-coated surfaces. Populations explode during the cool, moist conditions that characterize Western Washington's spring growing season.
Encourage lady beetles, hoverfly larvae, and parasitic wasps that naturally suppress aphid populations. A strong water spray dislodges colonies from sturdy plants. Reflective mulch around susceptible crops confuses incoming winged aphids. Reserve insecticidal soap for severe infestations that natural enemies cannot control, targeting colonies directly.
Quick Reference
Cultural Controls
- biological control Many parasites and predators attack aphid.
- Monitor the proportion of aphid mummies to unparasitized adults and the number of predators such as lady beetles.
- If the biocontrol agents appear to be gaining control, avoid sprays which would disrupt this system.
- Most products available for aphid control are highly disruptive of natural enemies.
- Management-cultural control Aphid populations tend to be higher in plants that are fertilized liberally with nitrogen.
- Prune out suckers...