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Current Insect Problems on Landscape Woody Ornamentals Catharine Mannion UF/IFAS Tropical Research and Education Center. Photos: H. Glenn, UF/IFAS. April 2014. The Landscape A Reservoir of Pests. Also a reservoir of natural enemies. Proper identification of The problem The pest
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Current Insect Problems on Landscape Woody Ornamentals Catharine Mannion UF/IFAS Tropical Research and Education Center Photos: H. Glenn, UF/IFAS April 2014
The Landscape A Reservoir of Pests Also a reservoir of natural enemies
Proper identification of • The problem • The pest CRITICAL for successful management
Invasive Pests are one of our biggest pest problems • Due to mild climate and diversity of plants, new insects become easily established • Approximately 1-2 new pests introduced each month
Pest Damage Photos by Glenn, UF
Do not always blame insects for damage. Other critters can also cause damage! Photos by Glenn, UF
Who did this? Photos: H. Glenn, UF/IFAS
Eggs Pupae/cocoons Cast skins Webs Frass Secretions Galls
Same insect ? YES Scale – females and males Photos: H. Glenn, UF/IFAS
Same insect ? YES Photos: H. Glenn, UF/IFAS
Whiteflies PUPA (NYMPH) ADULT Photos: H. Glenn, UF/IFAS Photo: H. Glenn, UF/IFAS
Same insect ? YES YES Photos: H. Glenn, UF/IFAS
What is this? Photos: H. Glenn, UF/IFAS All the same insect – Lobate lac scale
In addition to recognizing pests, you need to recognize the “good guys”
Pest ? NO YES Photos: H. Glenn, UF/IFAS
Pest ? NO YES
Pest ? NO YES Photos: H. Glenn, UF/IFAS
Pest ? NO YES Photos: H. Glenn, UF/IFAS
Which snail is the pest?Which snail is endangered? Stock Island tree snail Giant African land snail Photos: Bill Frank, www.jaxshells.org, D. G. Robinson, APHIS, Amy Roda, USDA APHIS
Is it a Pest ? • No physical characteristics that define a pest • Need to look at where it is and what it is doing • Need to be familiar with the common pests/natural enemies • Invasive pests are difficult • When in doubt – send to a proper authority
Awareness of new pests is very important. Of 150 species introduced into Florida during 1986-2002, 57% were first found in Monroe, Miami-Dade, Broward, or Palm Beach Counties. 27 new pests were reported for 2009-2010
The Biggest Invaders • Hemiptera (Suborder Sternorrhyncha) • Psyllids, whiteflies, aphids, scales, mealybugs • Often cover themselves in wax or froth Photos: H. Glenn, UF/IFAS
The Biggest Invaders • Coleoptera (beetles) P. Skelley, A. E. Mayfield III, M. C. Thomas, FDACS DPI; J. Hulcr, MSU, forestryimages.org; H. Glenn, UF/IFAS
The Biggest Invaders • Thysanoptera (thrips) H. Glenn and L. Osborne, UF/IFAS
The Biggest Invaders • Mites
Hemipteran Pest Damage(aphids, whiteflies, scales, mealybugs) • Changes in foliage • Discoloration, spots, stippling, yellowing, bronzing) • Defoliation and branch dieback • Overall plant decline • Plant death • Prolonged infestations • Secondary stress
Signs of Infestation by Hemipteran Pests • Cast skins • Mummies • Wax • Tar spots • Honeydew • Sooty mold Photos: H. Glenn, UF/IFAS
Management Hemipteran Pests • Early detection • Often cryptic; not noticed until populations are high • Many have waxy secretions/coverings that provide protection • Wash with water • Insecticidal soaps and oils – need good coverage/repeat application • Biological control • Insecticides - systemic vs. contact
Management of Pests with Systemic Insecticides • Several application methods and formulations • Soil application (drench, granular, pellets, injection) • Trunk application (basal spray, injection) • Foliar application • Excellent tools for pest control • Can provide long term control • Prone to overuse
Granular Drench Injection Trunk spray
Whitefly Management Ficus, Rugose Spiraling and Bondar’s Nesting Whiteflies
Pest Groups Targeted • Hemiptera • Adelgids • Aphids • Bugs • Leafhoppers • Mealybugs • Psyllids • Scales • Whiteflies • Coleoptera • Beetles • Weevils • Others • Ants • Fungus gnats • Craneflies • Leafminers • Thrips
Using Neonicotinoid Insecticides • There is no “best” a.i. or method - take advantage of the different methods and formulations • Fit the method(s) of application for the site • The site and method needs to be on the label • Consider the methods that gets the needed result with the least negative impact on the environment/non-targets
Neonicotinoid Applications Applied to the foliage Applied to the trunk Applied to the soil Movement of the insecticide is upwards
Neonicotinoid Insecticides • Application to coconuts (or fruits) • Landscape: ornamental vs edible plant • Effects on pollinators (particularly bees) • Toxic to bees • Systemic applications –use lowest effective dose • Avoid use on tree species highly attractive to pollinators; Use after bloom • Impact of other types of insecticides • EDIS ENY-162 Minimizing Honey Bee Exposure to Pesticides
Honey Bee HealthUSDA and EPA 2013 • There are multiple factors playing a role in honey bee colony decline • Forces impacting honey bee health are complex • Parasitic Varroa mite – major factor • Bee viruses – major factor • Poor genetic diversity • Poor nutrition among honey bee colonies • Need to determine actual pesticide exposure and effects to bees in the field
Insecticide Resistance • Resistance to insecticides - not a new problem • Ongoing efforts with pyrethroids and neonicotinoids, the two biggest selling classes of insecticides • Repeat application (particularly in multiple generations) • Exposure to sublethal (less than optimal) pesticide rates • How does systemic use affect resistance?
Arthropods Prone to Resistance Development • Mites, aphids, whiteflies, and thrips • Many generations per year • Exposure of multiple generations to a pesticide • Produce many offspring • Limited dispersal • Exposure to sublethal (less than optimal) pesticide rates
Resources on Insecticide Resistance • Managing Insecticide and Miticide Resistance in Florida Landscapes - http://edis.ifas.ufl.edu/in714 • Management of Insect and Mite Resistance in Ornamental Crops - http://edis.ifas.ufl.edu/in715 • A Dresser Drawer Method of Managing Insect and Mite Resistance in Ornamentals - http://edis.ifas.ufl.edu/in773 • IRAC’s Insecticide Mode of Action classification - http://edis.ifas.ufl.edu/pi121
Biological Control • Natural first line of defense • Conservation of natural enemies • Everything you do has some impact • Reduce negative impact • Release natural enemies • Requires knowledge of both the pest and natural enemy
Integration of Biological Control and Pesticides • Most broad spectrum insecticides are toxic to arthropod natural enemies • Fungicides are toxic to many entomopathogens • Acaracides and pyrethroids – most harmful to predatory mites • Pyrethroids – selective on most lacewings; mixed results on other predators and parasites
Integration of Biological Control and Pesticides • Organophosphates – toxic to most arthropod natural enemies • Botanicals – mixed effect on natural enemies; some selection • Growth regulators – usually more specific; some selection • Neonicotinoids – low to moderate (depends on application)
Impact of “Lower Risk” Pests • Risk of spreading into production areas • High visual or local impact • Public, press and politic pressure • Yet, not considered national risk (lack of funding or resources) • Could be more problematic in isolated areas • Reliance on pesticides
Established Pest Populations • These pests are not going away • Expect populations to go down (takes years) • May always have “hot spots” • Diverse landscapes • Overplanting anything (including native plants) can create a problem • Select trees with less problems (but this is dynamic and can change; i.e. ficus) • Strive for biologically based, long-term pest management
Web Resources • http://trec.ifas.ufl.edu/mannion • http://mrec.ifas.ufl.edu/lso/IAWG/ • http://edis.ifas.ufl.edu/ • http://creatures.ifas.ufl.edu/ • Pest Alerts • University of Florida (http://extlab7.entnem.ufl.edu/pestalert/) • DOACS (http://doacs.state.fl.us/~pi/enpp/pi-pest-alert.html)
Whitefly Update Photos: H. Glenn, UF/IFAS
Ficus Whitefly Photo: H. Glenn,, UF/IFAS