The ARRIVE Essential 10 and The Recommended Set; Author Checklist (Insect Colonization)
Description
This study investigated the impact of Flunitrazepam (Rohypnol) on insect colonization and decomposition patterns in a forensic context. The research hypothesis was that increasing concentrations of Flunitrazepam would reduce the abundance of insects attracted to decomposing remains and prolong the duration of decomposition stages, while not significantly altering the pattern of insect succession. To test this, four domestic pigs (Sus scrofa Linnaeus) were used—one as a control and three as experimental units receiving oral doses of Flunitrazepam at concentrations of 1 mg/250 ml, 2 mg/250 ml, and 3 mg/250 ml dissolved in vodka. After euthanasia, the carcasses were placed in individual metal cages at the University of Nairobi’s Veterinary Farm, Upper Kabete, and left to decompose under natural conditions. Insect sampling was conducted over a 60-day period using aerial nets, pitfall traps, and forceps. Sampling frequency was three times daily for the first eight days, twice daily for the next eight days, and once daily thereafter until decomposition reached the dry remains stage. Samples included adult insects and maggots collected from the body surface, natural openings, and surrounding area. Maggots were either preserved in 75% ethanol or reared to adulthood for identification. Insects were identified using standard entomological keys and recorded by species and abundance. The first dataset contains insect species occurrence, developmental stages, and temporal distribution across the five decomposition stages (fresh, bloated, active decay, advanced decay, and dry). The second dataset includes meteorological data—such as temperature and humidity—collected daily from the study site to provide context for environmental influences on decomposition and insect activity. Key findings show that insect abundance decreased as Flunitrazepam concentration increased, but the composition and succession pattern of insect species remained consistent. Calliphoridae was the most dominant family across all carcasses. Decomposition was slower in Flunitrazepam-treated carcasses, indicating the drug’s potential to delay insect colonization or development. These data are useful for forensic scientists and entomologists investigating drug-related deaths, post-mortem interval estimation, and carrion ecology. Researchers can use this dataset to examine drug effects on decomposition dynamics, validate forensic models, and compare findings across different environmental or geographic contexts.
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Steps to reproduce
To reproduce this study and data collection process, the following steps and protocols were followed: 1. Animal Selection and Preparation o Four healthy domestic pigs (Sus scrofa domesticus), each weighing between 24.6–25.0 kg, were obtained from the veterinary farm of the University of Nairobi’s Faculty of Veterinary Medicine o One pig was assigned to the control group. The other three received Flunitrazepam orally in doses of 1 mg/250 ml, 2 mg/250 ml, and 3 mg/250 ml, each dissolved in vodka to simulate human drug ingestion scenarios. o After drug administration, the pigs were humanely euthanized using electrical stunning. 2. Carcass Placement o Carcasses were placed outdoors at the University of Nairobi’s Veterinary Farm, Upper Kabete, in identical metal cages (92 × 92 × 153 cm) spaced 100 meters apart to prevent scavenger access and environmental overlap. o The site was a semi-wooded area with minimal canopy cover and natural soil, allowing environmental exposure. 3. Insect Sampling Protocol o Sampling was conducted three times daily (7 AM, 1 PM, and 7 PM) for the first 8 days, twice daily (11 AM and 5 PM) for the next 8 days, and once daily (12 PM) until all carcasses reached the dry remains stage (~60 days). o Sampling tools included aerial sweep nets for flying insects, pitfall traps (plastic cups with soapy water) for crawling arthropods, and forceps for maggot collection from natural orifices and wounds. o Each sample was labeled with time, date, carcass ID, and environmental notes. 4. Preservation and Identification o Flightless insects were either preserved in 75% ethanol after brief immersion in boiling water or reared on meat until adulthood for species-level identification. Adult, flightless insects and other specimens were identified using standard entomological keys based on morphological features. o Sampling focused on key forensic insect families: Calliphoridae, Muscidae, Sarcophagidae, and Coleoptera. 5. Meteorological Data Collection o Environmental variables, including temperature and humidity, were recorded daily using a portable digital weather station placed at the study site to provide context for interpreting insect activity and decomposition progression. 6. Data Analysis o Insect abundance and diversity data were organized and analyzed using Microsoft Excel and SPSS version 25. o Statistical analysis was employed to assess species distribution across decomposition stages. o Independent t-tests compared insect abundance between experimental groups. Following these steps with comparable environmental conditions, specimen types, and sampling frequency will allow accurate replication of the study and its data outputs.