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Calcimator

Nematode Assessment Calculator

Calculate biological control agent release rates for augmentative biocontrol programs based on pest density and predator-prey ratios.

Inputs

Results

Agents per release

167

Total agents for season

1,002

Agents per acre per release34
Total release events6
Estimated total pest population1,000
Expected suppression (%)9.7
How to Use This Calculator
  1. Enter Field area (acres), Pest density (per acre), and Predator:prey ratio.
  2. Set Agent search efficiency (0-1), Release interval (days), and Treatment season (weeks).
  3. Review Agents per release and Total agents for season.
  4. Use Agents per acre per release and Total release events to inform your decision.

How the result changes with Field area (acres)

Field area (acres)Agents per releaseTotal agents for season
1,00033,334200,004
3,500116,667700,002
6,500216,6671,300,002
9,000300,0001,800,000

What each input means

Field area (acres)
Total area to be treated with biological control agents.
Pest density (per acre)
Average pest count per acre from field sampling.
Predator:prey ratio
Desired ratio of agents to pests (e.g., 0.1 = 1 agent per 10 pests). Inundative: 0.2-0.5, Inoculative: 0.02-0.1.
Agent search efficiency (0-1)
Proportion of pests an agent can find and attack. Specialist parasitoids: 0.6-0.9, generalist predators: 0.2-0.5.
Release interval (days)
Days between successive releases. Weekly releases are common for augmentative programs.
Treatment season (weeks)
Total duration of the biocontrol program in weeks.

What each result means

Agents per release
Number of biological control agents needed per release event.
Agents per acre per release
Agent density per acre for each release.
Total release events
Number of releases over the full treatment season.
Total agents for season
Total biological control agents needed for the entire program.
Estimated total pest population
Total pest population across the entire field area.
Expected suppression (%)
Estimated pest suppression percentage based on the Nicholson-Bailey model.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Field area (acres) = 5, Pest density (per acre) = 200, Predator:prey ratio = 0.1, Agent search efficiency (0-1) = 0.6 = 6 input(s) provided
  2. Calculate Agents per release
    Agents per release
    167 = 167
  3. Calculate Total agents for season
    Total agents for season
    1002 = 1002
  4. Calculate Agents per acre per release
    Agents per acre per release
    34 = 34
  5. Calculate Total release events
    Total release events
    6 = 6

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