Acacia Whiteflies in the Low Desert

DESCRIPTION:

Eggs: Laid on the acacia leaf

Nymph: Found on the upper side of the leaf, the black nymphs resemble ground pepper. Under magnification, these nymphs resemble small rounded black shells with white fringe protruding out from the edges of the shell.

Pupa: The nymph forms a shell and develops into a pupa.

Adult: Tiny white winged insects covered with a white powdery substance. Many acacias are so heavily infested that shaking the limbs results in a white cloud of insects taking flight from the tree. While acacia trees are the favored host, Acacia Whiteflies will also feed on mesquites and other desert trees with fern like leaves.

DAMAGE:

In each stage of its life acacia whiteflies suck fluids from the leaves and secrete a sticky "honeydew" substance. This makes a clear, shiny coating on the leaves, stems and branches. Whiteflies feed by scraping at the undersides of leaves so over time the insect feeding causes leaves to go from dull green to yellow to brown and finally die. While the acacia whitefly will not kill the tree, it may cause them to become unsightly or even partially or totally defoliated. This could result in shade loving plants growing under the acacia to be exposed to sunburn.

MANAGEMENT:

• No management is necessary. The whiteflies will not kill the tree. Frequently they are parasitized by Aphidius wasps.

• Insecticidal Soap

Links to more information on Whiteflies

• USDA Whitefly Knowledge base
• Silverleaf Whitefly Information Page, University of California, Kearney Agriculture Center
• University of California IPM Whitefly Fact Sheet