Insecticidal control

Soil application of systemic insecticide by licensed applicator for sustained control of ACP. Photo credit: CDFA

Because Tamarixia and other natural enemies of ACP are unlikely to completely halt the spread of the HLB bacterium, robust protection of citrus trees will require some form of insecticidal control.

The most effective treatment for ACP is a combination of Tempo (cyfluthrin) spray combined with a soil drench of systemic Merit (imidacloprid) applied by a licensed applicator.

Homeowners can apply their own foliar sprays (Sevin, Malathion) when psyllids are observed. Softer foliar insecticide options include horticultural oils and insecticidal soaps. However, these products must make direct contact with psyllids to kill them and the residues are short lived, so they must be applied more frequently.

Homeowners can also apply systemic imidacloprid (Bayer Advanced Fruit, Citrus & Vegetable). This soil drench should be applied during summer or fall when roots are active.

Type of treatment	Pesticide Name	Effectiveness against ACP	Duration of control	Application timing
Professional treatment	Tempo & Merit	High	Months	Foliar: when psyllids are present Systemic: summer or fall
Homeowner-applied broad-spectrum foliars	Sevin, Malathion	Moderate	Weeks	When psyllids are observed
Homeowner-applied soil drench	Bayer Advanced Fruit, Citrus & Vegetable	Moderate	Months	When psyllids are observed in summer or fall
Homeowner-applied soft foliars	Insecticidal soaps, oils and pyrethrins	Low to moderate	Days	Every 7-10 days during *leaf flushing

*Flushing: when new leaves are first developing until they expand and harden

Treatment Considerations

always follow label instructions for the safe and effective use of the product
only apply pesticides if psyllids have been observed or are known to be in your neighborhood
only apply insecticides to host plants of psyllids (citrus and closely related hosts)
avoid using insecticides during blooming periods to limit impacts on pollinators
good coverage, including undersides of leaves, is important for foliar sprays
If Tamarixia wasps have been released near your home, then use softer insecticides (oils and soaps) that are safer for the Tamaraxia and be sure to control ants (UC IPM guidelines for ant control).