Integrated Pest Management IPM concepts and grower training

Integrated Pest Management (IPM) concepts and grower training needs in Hawaii’s tropical fruit industry Is IPM a sustainable approach to managing pests? [Sustainable: “method of using a resource so that the resource is not depleted or permanently damaged”] Pest Control – often creates its own problems – can lead to permanent “damage”.

Pest Management vs. Pest Control • Pest management aims to maintain insect populations below a threshold; • Emphasis is not on eradication.

The UH IPM Verification Program IPM Implementation on 75% of Hawaii's Crop Acres by the Year 2001. Our highest priority is implementation to meet President Clinton’s goal for IPM implementation on 75% of the nations crop acres. http: //www. extento. hawaii. edu/IPM/

Verification is based on points allocated for: • Development and implementation of IPM procedures; • Monitoring, application of various options, justification for each action. • Farmer provides documentation for annual audit.

Insects – prevalent features of our environment • Number of species; • Interactions in ecosystems and with us; • Our major competitors.

Understanding insect numbers • May be explosive outbreaks • Seasonal changes in numbers; • What are the causes of changes in abundance?

• Insect ecology examines dynamics of insect numbers temporally and spatially; • Phenology and diversity are also important; • Interactions with plants and other insects.

• Ecology aims to explain how environment (biotic and physical) affects abundance, phenology and diversity of insects; • Therefore ecology forms the basis for pest management. • Understand both ecology and economy to implement IPM

Some history: Dealing with pests • Pre-insecticide era: 2500 B. C. : Sulfur, herbs and oils used to protect seeds and stored grain. • 300 B. C. : Plant phenology recognized as a means of avoiding pests; Chinese started using natural enemies of insects.

• By 1101, Chinese used soaps to control pests; • Late 1600’s: tobacco infusions , arsenic used. • 1700’s: Importance of temperature summation in determining insect phenology discovered! Plant resistance used in the USA; Botanical insecticides rediscovered.

• 1800’s: inspection and quarantine became important; • 1920 - 1930’s: Depended on crop sanitation, timing of planting, minor use of insecticides. • Insecticide era: ~1939 - 1962: DDT was discovered; Organophosphates later. • Purely insecticide-based approach to pest problems emerged. • 1962: Silent Spring by Rachel Carson

• The concept of Integrated Pest Management was developed. • Emphasized the selective use of insecticides, and conservation of natural enemies. Emphasis shifted from control to management. Tolerance, rather than decimation encouraged.

Elements of IPM: • Multiple tactics used in a compatible manner; • Pest numbers below levels that cause economic damage; • Consideration of environmental impact.

IPM = Sustainable Pest Management?

Aims of IPM: • Reduce pest populations to levels below those causing economic impact, using multiple, compatible techniques; • Reduce environmental impact of pest management.

Economic injury level Lowest number of insects that will cause economic damage.

Economic / Action threshold: Number of insects that should instigate management action

Economic decision levels - thresholds • Usually expressed as number of insects per area, plant, or sampling procedure • Sometimes use extent of plant damage • Include biological and economic information

Gain threshold • Expresses the beginning point of economic damage. • Insecticide application would have to save 5 bushels per acre to be profitable

Economic threshold • Also called Action Threshold – Insect density that would justify intervention • May be a fixed economic threshold: e. g. if EIL is 6 insects per plant, intervene at 4 insects per plant;

Number of Insects Economic loss Non-economic loss No loss Time

Time Number of Insects

IPM Options: • Biological control • Physical control • Cultural control • Chemical control Monitoring insect numbers is the cornerstone of IPM

Approaches to monitoring: Various methods: • Direct counts • Traps • Damage estimates • Prediction: degree-days

Benefits of monitoring: • Track numbers of pests and natural enemies; • Able to target insecticide applications at the correct time; • Enhances conservation of natural enemies; • Indicate efficacy of treatments.

Biological control: • Natural enemies of pests cause mortality; • Can maintain pest population at below-threshold levels Predators Parasitoids Pathogens

Types of BC: • Import natural enemies - establish in field Classical BC; • Augmentative releases: inundative or inoculative releases each season; • “Conservation” BC: depend upon local natural enemies. • All these approaches require conservation of natural enemies to be effective.

Conserving natural enemies Reduce insecticide use; Use softer chemicals; Manipulate habitats, e. g. intercropping.

Concerns: Biological Control • Non-target effects? • “Necessary evils: murder, drugs and biological control” (Lockwood 1999) • Host specificity testing • Risk assessment protocols?

Insecticides • Insecticides as resources: Huge financial investment for development; Potential for Use or Abuse of this resource; Can play an important role in providing options for pest management.

Problems with insecticides: • • Kill or disrupt natural enemies Secondary pests Residues on produce Build-up of resistance – insecticide “treadmill” • Environmental concerns

Build-up of resistance: 2 1 3 4

Dealing with resistance • • • Wrong approach: Raised concentrations of active ingredients! Increased frequency of application! Correct approach: Reduce reliance on chemicals. Alternation of chemical groups. Targeted insecticide applications.

Example of rotation program: Pyrethroids Organophosphates “Organics” IGR’s Carbamates CHC’s

Benefits of insecticides: • • Can be effective if used correctly Can provide an immediate solution New formulations are safer Target-specific modes of action are being developed • Effective chemicals should be conserved as a component of sustainable pest management programs.

Summary • IPM requires pest and beneficial insect identification; • Need effective means of managing these; • Require economic information; • Require training to encourage adoption.

Are fruit growers interested in IPM training and verification? • What are the needs of growers in terms of training? • Would verification be valuable to you? • Should we proceed to develop verification guidelines?

Mark G. Wright Department of Plant & Environmental Protection Sciences, CTAHR, UHM Tel: 808 956 -7670 Email: markwrig@hawaii. edu Website: http: //www. ctahr. hawaii. edu/wrightm