Biological Control In The Field Kris Braman University of Georgia

Why Use Natural Enemies? Pests? Control Alternatives Why “go biological” ? The pesticide “treadmill” Target pest resurgence Secondary pest outbreaks Pesticide resistance Fewer pesticides available Human health and environmental concerns

Know the Enemy- What is a Pest?

What is a Pest, really? Some Pests are Bigger than Others! Key Pests

Integrated Pest Management IPM Use of all available tactics to maintain pests at acceptable levels including: Mechanical Biological Cultural Chemical Regulatory

Target Pest Resurgence

Secondary Pest Outbreaks

Pesticide Resistance

Registered Pesticides ( )‏

Key Factors in Successful Pest Management Scouting Proper Diagnosis Deciding on Control Tactic Implementation Follow-up Assessment

Turfgrass Food Web Chinch bugs Spittle bugs Caterpillars Grubs Big-eyed bug Parasitoid Wolf spider Ground beetles Tiger beetle

Ecological Basis of Biological Control Add density dependent mortality factor increase biotic pressure reduced carrying capacity

Types of Biological Control

Conservation Protection of existing biological control agents may be accomplished by: Use of pesticides only when necessary Spot sprays rather than blanket coverage Choice of pesticide that is least toxic to beneficials Avoid or be selective in applying broad spectrum or persistent pesticides Planting a variety of flowering species to provide nectar and pollen sources and sources of alternative prey for predators Providing shelter and moisture sources

Azalea Lace Bug (Stephanitis pyrioides ) Azalea lace bug adult Azalea lace bug eggs Azalea lace bug nymphs

ALB feeding through stomates

Cell content evacuation in palisade parenchyma layer

Parasitic wasp that attacks and kills lace bug eggs Parasitized lace bug egg next to leaf midrib. Wasp has chewed a circular hole in the lace bug egg and emerged Mymarid wasp next to An azalea leaf hair

Five emergence peaks per year at 3 sites in a 2-yr study

Azalea plant bug (Rhinocapsus vanduzeei) adult and nymph, a predator that feeds on lace bugs, thrips, other small insects and pollen

Pest Resistant Plants

Azalea growth in response To azalea lace bug feeding Whole plant gas exchange measurements revealed that photosynthesis, carbon use efficiency and growth were not affected by lace bug injury < 13%

Augmentation Release of additional beneficials when existing populations are too low Inoculative release: small number released into an area of low pest infestation and progeny are sufficient to maintain low pest levels Inundative release: large numbers of natural enemies are released often several times during a season

Augmentation of Natural Enemies

Augmentative releases of natural enemies Uses in the US: Predaceous mites Increasing in use Improved rearing still based on natural foods Improved shipping and release systems envelopes with substrate, to place in plants Phytoseid mite consuming a spider mite Augmentative Releases

Mite predators PHOTO: Max Verkooy L.Hull

Monitoring for mites

Importation (Classical)‏ Used most often against pests that have been accidentally introduced to the area where they are currently a problem Natural enemies from the pest’s native region are introduced into the new area

Classical- Importation In 1990 estimated that 722 biocontrol agents previously introduced into the US had resulted in suppression of 63 insect and mite pests Most complete successes with Homopteran pests

PHM Parasite Release Program Media Covering Florida’s First Parasite Release

Pink Hibiscus Mealybug Host Plants Fruits  Papaya  Sugar-apple  Golden apple  Pigeon pea  Carambola  Soursop  Cherry  Passion fruit  Avocado  Mango  Plum  Grape  Citrus  Breadfruit  Guava  Banana Ornamental  Hibiscus  Croton  Allamanda  Anthurium  Heliconia  Lantana  Seagrape  Bougainvillea  Oleander  Ixora  Ginger lily  Schefflera  Ficus Vegetable  Tomato  Pumpkin  Okra  Lettuce  Beans  Cucumber  Peppers  Dasheen  Cabbage  Squash

PHM Populations Reduced by Parasitoids St. Kitts = 91.6 % US Virgin Islands St. Thomas = 91.2% St. Croix = 97.1% Puerto Rico = 92% Culebra = 96.5% Vieques = 97.8% Belize = 96.6% California Mulberry = 96% Carob = 93% Bahamas = 82% (1 year)‏ Florida = 98.7% Haiti = 97.2% Dominican Republic = 96.6%

Mole Crickets

Identification and biology of some important predators The first step in effectively using biocontrol is to correctly identify common natural enemies and to know what pests they are active against Generalists vs. specialists Knowledge of the life cycle is important; many natural enemies attack only a particular stage of a pest (egg, larva)‏

Spiders

PREDACEOUS MITE

Predatory beetles

LADY BEETLES

Turfgrass Cultivar Influences on Fall Armyworm Parasitism S. Kristine Braman Department of Entomology University of Georgia Tigers in the Turf Kris Braman University of Georgia

Predators in the “True Bug” group

Predatory flies

Green Lacewing

LACEWING CAMOUFLAGE

Mantids

Paper Wasps

Parasitic wasps and flies

Azalea lace bug egg parasite

SCALE WITH PARASITE EMERGENCE HOLES

TACHINID EGGS ON CATERPILLAR

FUNGAL PATHOGEN

SCALE PATHOGEN

Managing Naturally Occurring Parasites and Predators Choose selective rather than broad- spectrum insecticides May be slower, but long term control is better achieved by using methods that conserve natural enemies Monitor for beneficial arthropods as you would for pest insects If ratio of pests to natural enemies is low, then spraying can be delayed