Competition for food resources affects time-of-deathestimation variables in the forensic-relevant fly species Lucilia sericata and Calliphora vicina
In forensic entomology, larval density and competition for food resources among the first cadaver-colonizing insects can affect the accuracy and reliability of the estimated time of death as the minimal postmortem interval (mPMI). This study evaluated the impact of intra- and interspecific food reso...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Pontificia Universidad Javeriana
2025-07-01
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| Series: | Universitas Scientiarum |
| Subjects: | |
| Online Access: | https://revistas.javeriana.edu.co/index.php/scientarium/article/view/38715/31882 |
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| Summary: | In forensic entomology, larval density and competition for food resources among the first cadaver-colonizing insects can affect the accuracy and reliability of the estimated time of death as the minimal postmortem interval (mPMI). This study evaluated the impact of intra- and interspecific food resource competition within and between the forensically relevant fly species Lucilia sericata and Calliphora vicina on life history traits relevant to estimating mPMI. Intraspecific competition assays proceeded with 25, 50, 100, and 300 larvae on 25 g of beef liver. Likewise, interspecific competition experiments proceeded at three food resource levels (5 g, 50 g, and 150 g of beef liver) with 30 larvae (15 of each species). Intraspecific assays revealed a maximum increase of 4.3 °C above the ambient temperature in the larval masses of both species. In both species, larval size decreased with increasing larval density. Larval stage-specific mortality for L. sericata occurred predominantly between instars LII and early LIII, whereas in C. vicina, LI and LII instar larvae experienced the highest mortality. In the interspecies assays, the length and weight of adults of both species differed markedly, with L. sericata outcompeting C. vicina, demonstrating that food was the limiting resource determining adult sizes. This study provides valuable insights to enhance the accuracy of time-of-death estimates in forensic entomology contexts. This study unravels the intricate interplay of food resource availability, competition, and environmental factors in shaping the developmental dynamics of L. sericata and C. vicina at intra- and interspecific levels. A possible inverse relationship between larval density and survival rates may reflect the influence of competition and food availability, underscoring their relevance in understanding larval behavior and improving mPMI estimations. Additionally, the study reveals the advantage of L. sericata when competing under extreme food scarcity conditions, as evidenced by its survival rates and adult sizes. Considering the uniqueness of each forensic case and the interspecific competition for resources and microhabitats, analyzing the temperature of the mixed larval mass and the relative proportions of each species can enhance the accuracy of mPMI determinations. |
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| ISSN: | 0122-7483 |