How to Manage Pests
UC Pest Management Guidelines
DESCRIPTION OF THE PEST
Bean aphid is a dark, olive-green to black colored aphid. It is most easily confused with the cowpea aphid. Bean aphid has a dull matte appearance while the cowpea aphid is shiny. The cauda (tail-like structure) of the bean aphid has more hairs than that of the cowpea aphid and thus appears bushy. Except for the presence of wings, the winged form of the bean aphid is similar in appearance to the wingless forms.
Bean aphid may transmit celery mosaic but little is known in this regard. Bean aphid only occasionally builds up on carrots and little is known regarding economic thresholds and damage.
Bean aphids are attacked by a variety of common aphid predators and parasites. Lady beetles, green lacewing larvae, and syrpha name fly larvae are frequently found associated with aphid colonies. Bean aphid is also attacked by a very prolific parasitic wasp, Lysiphlebus testaceipes. Parasitized aphids become bloated and their bodies turn tan in color. Bean aphid is also attacked by a fungus disease that leaves the aphid body flattened and with the appearance of being glued to the leaf.
No cultural control strategies are presently available for managing bean aphids in carrots.
Organically Acceptable Methods
Biological and cultural controls are acceptable for use on organically grown produce.
Monitoring and Treatment Decisions
Monitor fields for aphids weekly during spring and summer by examining the upper and lower surfaces of leaves. Also, look for eva nameence of predators and parasites and their impact on aphid populations. Treatment is rarely required. No thresholds have been established for the treatment of bean aphid on carrots. Chemical treatments are not effective in preventing virus transmission and this aphid rarely causes economic damage.
UC IPM Pest Management Guidelines:
E. T. Natwick, UC Cooperative
Extension, Imperial County