Integrated Pest Management Ecology and Human Impact R. Bruce Chapman Insect Science Ltd
Pest organisms
When do organisms become pests? When an organism s population exceeds a threshold level, and control actions are warranted. Environmental conditions Food & water supplies Survival strategies Action by humans
Agricultural landscapes Characterised by: Low structural and spatial diversity Low species diversity Low genetic diversity Economic imperatives High inputs Few people
Urban landscapes Characterised by: High structural and spatial diversity High species diversity High genetic diversity Social, cultural and economic imperatives High inputs Many people
Main components of IPM programmes The use of compatible control tactics (chemical, cultural, biological) to maintain pest populations below economic thresholds. IPM Biological controls Cultural controls Mechanical/physical Chemical controls Pest ID Monitoring Economic thresholds
Kiwigreen IPM programme Pest complex key pests Pathogens Botrytis Sclerotinia Sclerotinia Botrytis Arthropods Leafrollers Scale insects LBAM Greedy scale
Kiwifruit insect pest monitoring Scale insects 1 leaf per bay, outside rows 2 leaves per bay Leafrollers 8 fruit clusters per bay on 1/3 of rows in a block. Bay Thresholds: scale insects 4% leaves infested leafrollers 0.5% fruit infestation/damage
Crop and pest phenology Hayward (Green) Zespri Gold Hort 16A Disease monitoring Bud burst Flowering Canopy growth Weather monitoring Insect monitoring Fruit development Harvest
Kiwigreen control tactics Conventional - Kiwigreen Organic Dormant sprays Dormant sprays Synthetic + soft insecticides Soft insecticides Synthetic fungicides Copper-based fungicides Monitoring to determine need for applications Withholding periods Bio-Gro standards IPM programme trends reduced use of hard chemicals reduced number of applications improved orchard management practices Perfect fruit
Insect population regulation NZ Plant Protection 57:191-195 (2004) Lower temp. threshold = 14.5 o C Centrodera = egg parasitoid Scolypopa = pest of kiwifruit Lower temp. threshold = 10 o C Synchronisation of parasitoid and host dependent on temperature and photoperiod.
Agrichemical use patterns 50 years ago Introduction of synthetic chemicals Broad-spectrum, persistent chemicals Calendar spray schedules (-) Supervised spray schedules Monitoring, decision making, application on an as-needed basis (+) Selective chemicals, selective use Tomorrow
Selection of resistant strains Selection of agrichemical resistance Two features are essential: - Presence of genes for resistance - Selection pressure Resistance level Applications Control failure Time
Impacts on non-target species Non-target organism = any organism not intended as a target for agrichemicals. Agrichemicals can have: acute effects chronic effects sublethal effects Beneficial species Predators Parasitoids Pollinators Pathogens
Agrichemical Residues Gas chromatograph Residue level (ppm) Active ingredient MRLs International market access Time (days)
Techniques in biological control Advantages - Reduced chemical use - Compatible with IPM programs -Sustained pest management Classical biocontrol Applied biological control Disadvantages - Available natural enemies - Efficacy and speed of action - Easily disrupted - More difficult to use Conservation biocontrol Augmentation biocontrol
Effect of biological control agents on pests High Natural enemy introduced Pest density Economic threshold level Low Time
Classical biological control The importation and release of BCAs not present in a country: this technique involves collection, quarantine, rearing and release. Collection from country of origin. Multiple strains collected. Quarantine to ensure no other organisms also enter country. Specificity tests. Microctonus species ERMA DNA profiles for Microctonus sp. Rearing to bulk up sufficient numbers to release. Biological studies. Release multiple release times and sites. Ongoing monitoring.
Thank you for your attention I trust you have found this talk interesting Any questions? R. Bruce Chapman Insect Science Ltd insectscience@xtra.co.nz