Midterm 1

• Insects:

  • Highly diverse
  • Insect success influenced by body architecture, small size, flight for dispersal, and reproduction with short generation times and high genetic variability
• Arthropods have jointed appendages, divided segments, and hard outer exoskeleton
• Insecta has 3 regions (head, thorax, abdomen) with 3 pairs of legs and 2 pairs of wings
• 9 orders most responsible for pest problems:

  • Coleoptera
  • Diptera
  • Hymenoptera
  • Hemiptera
  • Blattodea
  • Thysanoptera
  • Lepidoptera
  • Orthoptera
• Insect life cycle:

  • One generation from egg to adult
  • Univoltine = 1 gen/year
  • Multivoltine = >1 gen/year
  • Delayed voltine = life cycle requires > 1 year
• Metamorphosis:

  • Ametabolous = no metamorphosis, grow larger with each molt
  • Hemimetabolous = incomplete metamorphosis
  • Holometabolous = complete metamorphosis with 4 distinct life stages
• Pests are anthropocentric

  • IPM involves 4 steps: Identify, Quantify, Evaluate, Undertake
• 2 main types of control:

  • Natural Controls: weather, climate, natural enemies
  • Applied Controls: reduction of insect populations through human intervention
• Insect Ecology:

  • Agroecosystem created and maintained to satisfy human wants and needs
  • Spatial dispersion of populations: random, aggregated (clumped), regular (uniform)
• Population equations:

  • Density = individuals / unit measure
  • Dispersion = spatial arrangement of individuals
  • Natality = birth rate - number of eggs / female laid per unit time
  • Mortality = death rate - death / per unit area or time
• Population growth:

  • (births + immigrants) - (deaths + emigrants)
  • Biotic potential and carrying capacity influence population growth
• Insect Development:

  • Knowing development rates helps predict insect life stages and manage time activities
  • Temperature has the greatest effect on development rate
• Degree Day Method:

  • Accumulation of heat units above and below a specific temperature in a 24hr period
  • Thermal constant determines the number of degree days required for each life cycle to occur
• Insect ID:

  • Injury causes physical harm to a valued commodity
  • Damage is the monetary value lost due to injury
• Economic thresholds in IPM:

  • Economic Damage, Economic Injury Level (EIL), Economic Threshold (ET)
  • Nominal thresholds when the relationship between injury and damage is not understood
• IPM Strategies & Pest Types:

  • Pest types include sub-economic, occasional, perennial, and severe pests
• Sampling and Monitoring:

  • Measures pest populations, environmental conditions, host status, and economic factors
  • Sampling estimates include absolute and relative methods
• Scouting in Cannabis:

  • Observing movement, checking leaves, stems, and foliage, inspecting closely, and using flagging tape for pest outbreaks
• Mechanical/Physical Control:

  • Physical methods involve removing or excluding pests with barriers or crushing
  • Environmental manipulation and cultural controls are used for pest management