CRPT

• PEST


  Any organism that interferes with the activities and desires of humans (FIFRA)
• PEST


  Any organism detrimental to humans (Glass, nd)
• PEST


  Organisms that diminish the value of resources in which man is interested (NRC, 1975)
• PEST


  Applies to all noxious and damaging organisms, including insects, mites, plant pathogens, weeds and vertebrates (OTA, 1979)
• Insects as pests


  Insects are pests when they are sufficiently numerous to cause economic damage (Debach, 1964)
• PEST


  An animal or plant whose population density exceeds some unacceptable threshold level, resulting in economic damage (Horn, 1988)
• In order for an organism to be considered a pest, a damaging stage of the organism must be present in high enough numbers to cause actual injury to something valued by people
• A pest must cause injury
• Being a pest is not an inherent property of a species but, rather, a species (along with its population and age distribution at a given time and place) and a human valuation of the item being injured or damaged
• Four things required to make a PEST

  • Pest species must be present at the right stage
  • Environmental criteria must be met
  • Crop must be a susceptible variety and growth stage
  • All of the above must occur at the same time
• Pathosystem Concept


  Pathogen – host – environment triad must all be right in order for an outbreak of disease
• Pest Complex


  The specific collection of pest species attacking a specific commodity or cropping system at any given time and location
• Categories of PESTS


  • Invertebrates (arthropods, mollusks)
  • Vertebrates (mammals, fish, birds)
  • Weeds (perennials, summer/winter annuals)
  • Plant Pathogens (fungi, bacteria, viruses, nematodes)
• Based on Occurrence


  • Frequently occurs on crop; close association; rice stem borer (Regular Pest)
  • Infrequently occurs; no close association; caseworm on rice, mango stem borer (Occasional Pest)
  • Occurs during a particular season every year; red hairy caterpillar; mango hoppers (Seasonal Pest)
  • Occurs on the crop throughout the year and is difficult to control chili thrips, mealy bug on guava (Persistent Pest)
  • Highly mobile and can infest crops for a short period of time through movement; Desert Locus (Migrants)
  • Normally not a problem until control tactics applied for another pest enable it to increase and cause damage; beetle species (Secondary Pest/Accessory species)
• General Equilibrium Position (GEP)

  The average density of a population over a long period of time, around which pest population tends to fluctuate due to abiotic and biotic factors and in the absence of permanent environmental changes
• Economic Threshold Level (ETL)


  The pest population at which control measures should be taken to prevent pest numbers from reaching the economic injury level (IRRI)
• Economic Injury Level (EIL)


  The pest population is large enough to cause crop losses more than the control (IRRI)
• Damage Boundary (DB)


  The lowest level of damage which can be measured
• ETL is always less than EIL
• Based on Threshold Levels

  • Key Pest (Most severe and damaging pests, GEP lies above EIL always, Persistent pests, The environment must be changes to bring GEP below EIL)
  • Major Pest (GEP lies very close to EIL or coincides with EIL, Economic damage can be prevented by timely and repeated sprays)
  • Minor Pest/Occasional Pest (GEP is below the EIL usually, Rarely they cross EIL, Can be controlled by spraying)
  • Sporadic Pest (GEP generally below EIL, Sometimes it crosses EIL and cause severe loss in some places)
  • Potential Pest (They are not pests at present, If environment changed may cause economic loss, GEP is always less than EIL)
• Injury


  Any change in quantity and/or quality of an individual plant or a crop, caused by a harmful organism or by abiotic factors such as hail and frost
• Damage


  Any reduction in quantity and/or quality of yield
• Loss


  The reduction in financial returns per unit area due to harmful organism
• Worldwide, an estimated 20-40% of crop yield is lost to pests and diseases
• Losses of staple cereal (rice, wheat, maize) and tuber crops (potatoes and sweet potatoes) directly impact food security and nutrition
• Losses in key commodity crops such as banana and coffee have major impacts on both household livelihoods and national economies
• General Impact of Pests -- Injury

  • Consumption of plant parts
  • Chemical toxins, elicitors, and signals
  • Physical damage
  • Loss of harvest quality
  • Vectoring of pathogens
  • Direct contamination
• General Impact of Pests – Non-injury


  • Costs incurred to implement controls
  • Environmental and social costs
  • Regulatory costs (embargoes, quarantines, shipment costs, etc.)
• Crop Injury in More Detail

  • Tissue Injury to Leaves (Bleaching, Crinkling, Cupping and Curling, Edge Feeding, Hole Feeding, Mines, Mottling, Necrosis, Rolling, Skeletonization, Spots)
  • Structural Tissue Injury (Galls, Xylem injury, Phloem injury, Interference with structural support, Shape/appearance impact, Abnormal growth, Shoot dieback)
  • Root Injury (Fibrous Roots, Storage Organs)
  • Flower & Fruit Injury
• Weed Groups


  • Algae (aquatic systems)
  • Mosses/liverworts (turf & nurseries)
  • Ferns/horsetails (pastureland, horticultural crops)
  • Gymnosperms (rangeland, forests, long-term no-till systems)
  • Angiosperms [monocotyledon & dicotyledon] (annuals, biennials, perennials)
• IPM (Integrated Pest Management)


  Integrates management of all pests, Holistic approach; ecologically based, Can be applied to any ecosystem
• What does IPM integrate?

  • Multiple pest management tactics (chemical, biological, cultural, mechanical)
  • Management of multiple pests (insects, weeds, disease pathogens, nematodes, vertebrates, etc.)
  • Pest management tactics on an area-wide basis (many pest control situations are better handled on a large-scale or regional basis)
• IPM


  Reduces pests to tolerable levels, Does not emphasize pest eradication or elimination, Incorporates economic sustainability, Economic Injury Level and Economic Threshold concepts, Can also incorporate other important factors such as maintenance of environmental quality
• r thrips feeding injury on impatiens

  • Bean pod mottle virus in soybeans (left) vs. uninfected beans (right)
• Weed Groups


  • Algae (aquatic systems)
  • Mosses/liverworts (turf & nurseries)
  • Ferns/horsetails (pastureland, horticultural crops)
  • Gymnosperms (rangeland, forests, long-term no-till systems)
  • Angiosperms [monocotyledon & dicotyledon] (annuals, biennials, perennials)
• IPM has broad application
• IPM


  • Integrates management of all pests
  • Holistic approach; ecologically based
  • Can be applied to any ecosystem
• What does IPM integrate?

  • Multiple pest management tactics (chemical, biological, cultural, mechanical)
  • Management of multiple pests (insects, weeds, disease pathogens, nematodes, vertebrates, etc.)
  • Pest management tactics on an area-wide basis (many pest control situations are better handled on a large-scale or regional basis)
• IPM


  • Reduces pests to tolerable levels
  • Does not emphasize pest eradication or elimination
  • Incorporates economic sustainability
  • Incorporates economic Injury Level and Economic Threshold concepts
  • Can also incorporate other important factors such as maintenance of aesthetic quality
  • Incorporates environmental and social concerns
• Management


  A process by which information is collected and used to make good management decisions to reduce pest population impacts in a planned, coordinated way