Whiteflies in Southwest Florida

Transcription

1 Whiteflies in Southwest Florida 02/22/2013

2 Agenda What is a whitefly? What damage do whiteflies cause? How can whiteflies be treated? What is the future for whitefly problems?

3 What is a whitefly? Small, white, flying insect. Native to Belize, Guatemala, Mexico, etc Piercing/Sucking insect that feeds on sap. Adults congregate on the underside of leaves to feed and reproduce. Many species of whitefly exist, targeting a variety of host plant species.

4 Why do we have Central American Insects in Southwest Florida? Arrive through east coast ports. Insects thrive in climates with year round warmth. Typically Cold Snaps (read: consistent days with temps dipping into the 30 s) in Collier County control these insects. Lack of Cold Snaps in recent years have caused insect populations to flourish. Lack of natural predators.

5 Three common species in SW Florida Rugose Spiraling Whitefly Ficus/Fig Whitefly Cardin s Whitefly Host plants: Alexander Palms Areca Palms Birds of Paradise Christmas Palms Coconut Palms Fruit/Citrus Trees Gumbo Limbo Trees Over 85 species! Host plants: Ficus Hedges Ficus Trees Fig Trees Host plants: Duranta Plants

6 Whiteflies can be damaging Rugose Spiraling Whitefly Ficus/Fig Whitefly Cardin s Whitefly Damage: Honeydew excretion Mold buildup Mold deposits on property. Plant stress Plant discoloration Contagion to other species Damage: Total defoliation Leaf discoloration Branch die back Rapid plant death Damage: Total defoliation Leaf discoloration Branch die back Rapid plant death

7 Continued damage can be expected if untreated. Continued production of honeydew resulting in black sooty mold deposits on plants, pool areas, driveways, etc Plant discoloration & decline. Potential for total defoliation of ficus hedging. Cross species spreading.

8 Various treatment options are available and marketed Foliar Spraying Soil Drenching Granular Scattering Basal Bark Treatment Direct Trunk Injections

9 How do they work? Foliar Spraying: Utilize contact/systemic insecticides to kill insects currently infesting foliar structure. Pros: Kills all insects currently on plant. Cons: Kills beneficial insects. Unable to spray tall trees & palms without significant environmental impact. Provides limited term protection. Verdict: Effective in conjunction with drenches on low lying plants at assisting in immediate, short term knock down of infestations.

10 How do they work? Soil Drenching: Apply systemic insect control to the soil surrounding a plant for root uptake. Pros: Provides long term, systemic protection on low lying plants. Protection up to one year. Does not kill beneficial non sucking insects. Cons: Takes time for effectiveness. Limited effectiveness on palms. Verdict: Effective for low lying plants, hedges, etc Less effective for tall plants.

11 How do they work? Granular Scattering: Apply granular systemic insect control around base of a plant for root uptake. Pros: Provides long term, systemic protection on low lying plants. Does not kill beneficial non sucking insects. Cons: Takes time for effectiveness. Limited effectiveness on tall palms. Chemistries often leach out of soil before product can be absorbed. Verdict: Effective for low lying plants, hedges, etc Less effective for tall plants.

12 How do they work? Basal Bark Treatment: Apply systemic insect control directly to porous trunks of certain tree types. Pros: Provides long term, systemic protection on low lying plants. Direct absorption into tree ensures uptake. Does not kill beneficial non sucking insects. Eco Responsible approach (less required chemical) Cons: Takes time for effectiveness. Effective only on certain tree types (Gumbo Limbo, etc ) Verdict: Effective for certain tree types, but ineffective for palms and other less porous, woody trunked tree types.

13 How do they work? Direct injection treatment: Apply systemic insect control directly to Xylem tissue of trees via injection sites. Pros: Provides long term, systemic protection on low lying plants. Direct absorption into tree vascular structure ensures uptake and distribution to fronds. Does not kill beneficial non sucking insects. Eco Responsible approach (less required chemical) Very rapid effectiveness (72 Hours) Cons: Effective only on certain tree types (Palms, etc ) Verdict: Effective for certain tree types, but ineffective for Gumbo Limbo trees and other plants with very thick, viscous sap.

14 How will we treat? Examples: Coconut Palm Injection Christmas Palm Injection Areca Palm Cluster Foliar Spray / Drench Birds of Paradise Foliar Spray / Drench Gumbo Limbo Tree Bark App / Drench Fruit Tree Foliar Spray (Organic) Ficus Hedging Foliar Spray / Drench

15 Can we get away with cheaper treatment alternatives? Coconut Palms Injection Drench? Christmas Palms Injection Drench? Yes, but we lose control, effectiveness, and protection duration. Palms can be guaranteed for six months with injections. Treatment is typically effective even longer.

16 Will we see whiteflies in the future? Whiteflies are an invasive pest with a limited threat from natural predators in SW FL. Infestation risk decreases if infestation regions are controlled. We guarantee treatments for 6 months, but up to 1 year of control can be expected. UF Collier Extension timeline: 3 5 years until we see assistance from natural predators incline to take advantage of populations. The impact of climate, natural predators, and preventative/curative treatments all play a role in how long we ll be dealing with this magnitude of infestation.

17 Whiteflies in Southwest Florida 02/22/2013