Integrated Pest Management for Insects and Mites in Greenhouse Production PSS 127 Greenhouse Operations and Management

What is Integrated Pest Management (IPM) ?  An intelligent selection and use of pest-control actions that will ensure favorable economic, ecological and sociological consequences. 1 1 R.L Raab 1972.

Why IPM?  Collapse of Control Systems.  Pesticide resistance.  Loss of pesticide registrations.  Health risks associated with pesticides for agricultural workers and consumers.  Loss of natural enemies brought on new pest outbreaks.

Why Greenhouses?  Controlled environments  Semi-closed or closed production areas  Discreet number of insect pests  Monoculture v.s. Polyculture

Basic IPM  Pest Identification  Monitoring or Scouting  Threshold and Action Levels  Tactics: Cultural, Mechanical, Physical, Biological, and Chemical  Evaluation

Case #1 Two Spotted Spider Mite (TSSM)  Tetranychus urticae  Huge host plant range  Oval body, four pairs of legs.  Pale yellow-green or red with a dark spot on each side of the body.  Known for developing resistance to many pesticides.

Crop Damage

TSSM Biology

Two Spotted Spider Mite Biology

IPM Steps  1. Identification: yes, TSSM  2. Monitoring: How? What?  Use Scouting Methods.  Record Environmental Conditions.

Scouting Equipment Hand Lens Optivisor Sticky yellow trap cardsScouting records

Trap Cards as Scouting Tools  Yellow cards trap winged aphids, whiteflies, thrips, fungus gnats, and shore flies.  One card/250 – 1000ft 2  Horizontal is better for trapping fungus gnats.  They may snag natural enemies too.

Plant Inspection  Look at: New tip growth Mature leaves Senescent leaves  Return to known problem areas.  Avoid edges.

Thresholds and Action Levels  Problems: 1. Growers want to avoid risks; especially with high value crops. 2. Once the threshold level is reached, the probability of partial or total crop loss is high.

IPM Tactic: 1. Cultural Control Weeds inside the greenhouse Weeds outside the greenhouse Sanitation Cultivar Selection

IPM Tactic: 2. Mechanical Control  Using physical objects or devices to control pests.  Insect screening on intake vents, exhaust fans, and entrances.  microns  Restricts air flow.  Electric Bug Zappers.  Insect Vacuums.

IPM Tactic: 3. Physical Control  Altering environmental conditions to discourage pest infestation.  Temperature  Relative Humidity Case #1 TSSM: High Humidity discourages TSSM flare-ups.

IPM Tactic: 4. Biological Control  Definition: Biological control is any activity of one species that reduces the adverse effects of other species.

Types of Natural Enemies PredationParasitism HerbivoryCompetition

Case #1 TSSM Biological Control - Predatory mite: Phytoseiulus persimilis Two Spotted Spider Mite Phytoseiulus persimilis

P.persimilis controls TSSM on cucumber, sweet pepper, tomato, eggplant, bean, cut flowers, strawberries and many field crops.

Bio-control: Parasitism Case #2 Whitefly Control Common Pest of Greenhouse Tomato Greenhouse WhiteflySilverleaf Whitefly

Bio-controls: Parasitic Hymenopterans Female Encarsia formosa Greenhouse Whitefly Parasitoid Silverleaf Whitefly Parasitoid

IPM Tactic: 5. Chemical Control  Old school: Broad Spectrum pesticides  New school: Bio-rational pesticides

Pesticide Efficacy  Correct pest identification.  Most susceptible pest life stage.  Good coverage.  Proper dosage.  Avoid tank mixes.  Rotate chemical families. Citrus Mealybug

Bio-rational Pesticides  Look for compatibility with natural enemies  Specific target pest  Specific life stage (IGRs)  Short residual time  Short Restricted Entry Interval (REI)

Case #3 Green Peach Aphid (GPA) Myzus persicae Unwinged GPA adults and nymphsAphid damage Winged GPAESM GPA

Natural Enemies of Myzus persicae Aphidoletes aphidimyza Chrysoperla carnea Aphidius colemaniMummified aphid

Side Effects of Pesticides on Natural Enemies  Mortality of eggs, immatures or adults.  Reduced fertility.  Effect moulting.  Repellency

AzadirachtinInsecticidesPyriproxyfen Horticultural oil Insecticidal Soap Natural Enemy Aphidius colemani ? Mummy 25% Adult 0 persistence 25%75% ½ week 25%25% 0 persistence ?100%? Chrysoperla carnea 25% larva ? < 3 weeks 25%75% 0 persistence 25%25% 100%100%? Steinernemafeltiae 25% larva 0 persistence ??25% 100%? Compatibility of Bio-rational Pesticides and Natural Enemies (Koppert)

Evaluation  Successful Crop  Cost (materials, labor, health risks, environmental damage)  Multiple tactics?  Ease of operation  What would you do differently next season?

Mealybug predator Cryptolaemus montrouzieri

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