Histeridae - Importance in Forensics

Importance in Forensics

Forensic Entomology is the study of insects related to crime scenes. Insects can be very helpful at a crime scene and give people an idea of what happened and when it happened.

Flesh eating insects arrive at the dead body within a few hours. Certain species of the Hister beetles follow shortly behind and prey on the maggots and other arthropods present. Insects that feed on dead bodies increase the rate of decomposition and their mandibular mouth parts can cause excess damage to the body. Insects can also help determine the season the body died in. The Hister beetle is more prevalent in Spring and Summer.

The family, Histeridae, is very diverse, so different species can be found on the body at different times because of their various feeding habits. This needs to be noted when examining a dead body. They are predacious beetles and arrive when there is material to feed on, like other beetles or maggots. They do not actually feed on the carrion. For example, Hister quadrinotatus and Hister sedakovi arrive to feed when the carrion is bloat to dry (full of maggots to no maggots). In contrast, Saprinus pennsylvanicus arrive at the body first, when it is fresh to late (beginning of decomposition to advanced decomposition).

The Hister beetles lay their eggs in dead bodies and over a short period of time they develop into various stages. The Histeridae larvae are destructive and when they hatch they eat the maggots in the dead body. The stage of the beetle and other insects in the body at the time of investigation helps to determine the time of death. "Beetle larvae are ... helpful when determining post-mortem time interval. Beetle larvae often reside in fly breeding resources, and they can be distinguished from fly larvae by the following: Beetle larvae possess a hard, head capsule, often brown in colour. Fly larvae lack a head capsule, instead having distinct, internal, black mouth hooks (cephalopharyngeal skeleton of mouthparts) at the anterior end of their body." Understanding how long ago the eggs were laid and the time period of the developmental stages is important for determining the time of death.

The Histers beetles will hide under the dead body in the soil during the day and come out at night to feed. For this reason, the dead body must be examined at different times of the day. After collecting the Hister beetles from a body, isolate them because they are predacious beetles and eat anything in their way.