Ants (Hymenoptera: Formicidae) Associated with Pig Carcasses in an Urban Area

The study of cadaver fauna is the most important aspect of forensic entomology, and it is based on successional patterns of insects that feed on decaying carcasses. Many ant species have scavenger lifestyles, and thus have the potential for use in forensic entomology studies. There are no previous studies of ant fauna as forensic entomology tools in state of Maranhão. Here we characterize ants found on domestic swine carcasses at different stages of decomposition, with the goal of initiating a forensic entomology database in the state. We collected ants between November and December 2012 on two pig carcasses. A third carcass with no ant collection was used as a control to assess the influence of ant removal on decomposition rate. We captured 1,692 Formicidae in total, distributed among 10 genera and including 17 species. The most abundant species was Solenopsis saevissima, with 55.6% of relative abundance. Solenopsis was present at various stages of decomposition either feeding on carcass tissues or exudates, or preying on larval, pupal and newly emerged adult flies. Ants associated with this environment had high species richness and abundance in all stages of decomposition. We suggest that these insects influence the decomposition process either as facilitators (i.e., by laceration and fragmentation of tissue) or as hindering agents (i.e., due to predation upon other scavenging organisms)

Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) Activity Delays Vertebrate Carcass Decomposition

Ants are among the insects involved in cadaveric decomposition processes, as they exhibit predatory and necrophagous behavior. Red ants exhibit an aggressive behavior, which impacts carcass colonization, accelerates or delays the decomposition rates and potentially confounds interpretation of the post-mortem interval. Here, we estimated the effects of Solenopsis saevissima (Smith) activity on the decomposition rate in domestic pig carcasses. We placed two pig carcasses close to S. saevissima nests, and two other pig carcasses (controls) in other locations 50 m away from the nest. Decomposition processes were delayed by at least three days for carcasses on the nest compared to those without direct exposure to ants. Our results showed that predatory activity of S. saevissima interfered with carcass colonization by scavenger insects, functioning as an ecological barrier to the establishment of immature Diptera. Such results highlight the importance of considering ecological processes that may interfere with mechanisms determining post-mortem intervals

Ants (Hymenoptera: Formicidae) Associated with Pig Carcasses in an Urban Area

The study of cadaver fauna is the most important aspect of forensic entomology, and it is based on successional patterns of insects that feed on decaying carcasses. Many ant species have scavenger lifestyles, and thus have the potential for use in forensic entomology studies. There are no previous studies of ant fauna as forensic entomology tools in state of Maranhão. Here we characterize ants found on domestic swine carcasses at different stages of decomposition, with the goal of initiating a forensic entomology database in the state. We collected ants between November and December 2012 on two pig carcasses. A third carcass with no ant collection was used as a control to assess the influence of ant removal on decomposition rate. We captured 1,692 Formicidae in total, distributed among 10 genera and including 17 species. The most abundant species was Solenopsis saevissima, with 55.6% of relative abundance. Solenopsis was present at various stages of decomposition either feeding on carcass tissues or exudates, or preying on larval, pupal and newly emerged adult flies. Ants associated with this environment had high species richness and abundance in all stages of decomposition. We suggest that these insects influence the decomposition process either as facilitators (i.e., by laceration and fragmentation of tissue) or as hindering agents (i.e., due to predation upon other scavenging organisms)

Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) Activity Delays Vertebrate Carcass Decomposition

Ants are among the insects involved in cadaveric decomposition processes, as they exhibit predatory and necrophagous behavior. Red ants exhibit an aggressive behavior, which impacts carcass colonization, accelerates or delays the decomposition rates and potentially confounds interpretation of the post-mortem interval. Here, we estimated the effects of Solenopsis saevissima (Smith) activity on the decomposition rate in domestic pig carcasses. We placed two pig carcasses close to S. saevissima nests, and two other pig carcasses (controls) in other locations 50 m away from the nest. Decomposition processes were delayed by at least three days for carcasses on the nest compared to those without direct exposure to ants. Our results showed that predatory activity of S. saevissima interfered with carcass colonization by scavenger insects, functioning as an ecological barrier to the establishment of immature Diptera. Such results highlight the importance of considering ecological processes that may interfere with mechanisms determining post-mortem intervals