Minimum Base Temperature
Definition
The temperature below which blow fly larval development effectively stops. This threshold varies by species: Lucilia sericata is typically around 9 degrees C, while Calliphora vicina, a common cold-adapted UK species, has an estimated minimum of approximately 1-2 degrees C. Only temperatures above the species-specific threshold contribute to accumulated degree calculations.
- Lucilia sericata threshold
- Approximately 9 degrees C
- Calliphora vicina threshold
- Approximately 1 to 2 degrees C
- Used in
- Accumulated degree day/hour PMI calculations
- Species-specific
- Yes, determined per species from rearing studies
Common questions
What happens to a PMI estimate if the wrong minimum base temperature is used?+
Development time is miscalculated because degree-day accumulation only counts temperature above the true threshold. A species mismatch, for example applying a warm-adapted species value to a cold-adapted one, systematically shifts the estimated colonisation time and the resulting PMI.
Why does Calliphora vicina have such a low threshold compared to Lucilia sericata?+
Calliphora vicina is adapted to cooler climates such as the UK and continues developing at temperatures where warmer-adapted species like Lucilia sericata become dormant. This cold tolerance is why species identification must precede any temperature-based PMI calculation.
Is the minimum base temperature the same as the temperature at which larvae die?+
No, it marks where measurable development effectively stops, not a lethal limit. Larvae can survive somewhat below this threshold without accumulating meaningful growth, and separate lower lethal limits exist below that.
Related terms
- Development Table
- A species-specific reference dataset giving the accumulated temperature (degree hours or degree days above a threshold) required to complete each life-stage transition....
- Eclosion
- The emergence of the adult fly from the puparium. In rearing, the date of eclosion is recorded as the end point of...
- Isomorphen Diagram
- A contour plot of the same axes where each contour connects all (temperature, age) combinations that produce the same morphological developmental stage...
- Pupariation
- The process by which the third-instar larva contracts and hardens its own cuticle to form the puparial case (puparium) that encloses the...
- Rearing Medium
- The food source placed in the rearing container to support larval development. Raw beef liver is the standard; it provides protein, moisture,...