Gypsy Moth Egg-Mass Defoliation Threshold Checker
Screen observed egg-mass surveys with differential detection against caller density threshold; no embedded outbreak/defoliation model, species attribution or treatment recommendation.
Description
Egg-mass surveys can be corrected for imperfect detection before comparing densities.
Egg-mass surveys can be corrected for imperfect detection before comparing densities. A detection-adjusted inventory remains conditional on the supplied survey model.1
Screen observed egg-mass surveys with differential detection against caller density threshold; no embedded outbreak/defoliation model, species attribution or treatment recommendation.
When to use Gypsy Moth Egg-Mass Defoliation Threshold Checker
Use this tool to screen observed egg-mass surveys with differential detection against caller density threshold; no embedded outbreak/defoliation model, species attribution or treatment recommendation.
Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.
How to use Gypsy Moth Egg-Mass Defoliation Threshold Checker and understand its results
- Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.
- Enter observedEggMassCounts, surveyedAreasHa, detectionProbabilities, callerEggMassDensityThresholdPerHa using the field table and calculation rules, then run the tool.
- Read adjustedEggMassDensitiesPerHa, aboveCallerThresholdFlags, pooledAdjustedEggMassDensityPerHa. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| observedEggMassCounts | Observed egg mass counts | list of number | Required |
| surveyedAreasHa | Surveyed areas ha | list of number | Required |
| detectionProbabilities | Detection probabilities | list of number | Required |
| callerEggMassDensityThresholdPerHa | Caller egg mass density threshold per ha | number | Required |
Pair nonnegative integer egg-mass counts, positive surveyed hectares and detection probabilities in (0,1]. Use a nonnegative caller threshold and return local adjusted densities, strict exceedance flags and pooled adjusted count per area.
Paired lists must be nonempty and have equal lengths.
adjusted density=count/(detection probability × surveyed ha) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| adjustedEggMassDensitiesPerHa | Adjusted egg mass densities per ha | list of number |
| aboveCallerThresholdFlags | Above caller threshold flags | list of number |
| pooledAdjustedEggMassDensityPerHa | Pooled adjusted egg mass density per ha | number |
{
"input": {
"observedEggMassCounts": [
10,
20
],
"surveyedAreasHa": [
0.1,
0.2
],
"detectionProbabilities": [
0.5,
1
],
"callerEggMassDensityThresholdPerHa": 150
},
"output": {
"adjustedEggMassDensitiesPerHa": [
200,
100
],
"aboveCallerThresholdFlags": [
1,
0
],
"pooledAdjustedEggMassDensityPerHa": 133.33333333333331
}
}Limitations and assumptions
The tool does not identify species, embed an outbreak model or recommend treatment.
Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Snag Density: Pool unequal-area snag surveys with caller differential detection and independent Poisson count error; unlike existing fixed-plot tree expansion, correction/uncertainty require extra measured assumptions. For a complementary task, use Bark Beetle Host Basal Area Hazard Rating: Classify measured host basal-area share under a caller dominance policy while retaining pooled inventory; host availability alone does not establish beetle outbreak probability or tree hazard.
References
Similar or alternative tools
- Snag Density
Pool unequal-area snag surveys with caller differential detection and independent Poisson count error; unlike existing fixed-plot tree expansion, correction/uncertainty require extra measured assumptions.
- Bark Beetle Host Basal Area Hazard Rating
Classify measured host basal-area share under a caller dominance policy while retaining pooled inventory; host availability alone does not establish beetle outbreak probability or tree hazard.