Colonisation
Definition
The event when gravid female blow flies (or other pioneer species) locate the body and deposit eggs or first-instar larvae. The entomological clock starts at colonisation, not at death.
- Field
- Forensic entomology
- Trigger
- Gravid female pioneer flies locate the body
- Action
- Deposit eggs or first-instar larvae
- Key point
- Starts the entomological clock, not the moment of death
Common questions
Why does colonisation not always happen immediately after death?+
Access delay factors such as concealment, indoor placement, wrapping, extreme cold, or darkness can prevent pioneer flies from reaching the remains for hours or days, which is why colonisation time and time of death are treated as separate variables.
How do investigators tell colonisation occurred at night versus during the day?+
Most blow fly species are diurnal and will not oviposit after dark, so if remains are found with development consistent with overnight colonisation, that points to either a nocturnally active species or a delay explained by scene conditions, prompting closer scrutiny of the timeline.
Related terms
- Access Interval
- Any period after death during which insects could not reach the body, whether through concealment, refrigeration, submersion, or wrapping. The access interval...
- Larval Age Method
- Estimating mPMI by identifying the oldest, most developed insect stage present, staging it against a developmental timeline corrected for local temperature, and...
- Minimum PMI (Period of Insect Activity)
- The elapsed time since the first insects colonised the body. Because access may have been delayed, this is a lower bound on...
- Post-Mortem Interval (PMI)
- The time elapsed between death and discovery or examination of remains. PMI estimation draws on multiple disciplines: soft tissue decomposition stage, insect...
- Succession Method
- Estimating elapsed time from the species assemblage on the body by matching it to a local succession sequence: a known ecological progression...