Entomotoxicology as a tool for solving criminal cases

Abstract

Entomotoxicology deals with the analysis of toxic substances contained in arthropods that feed on dead bodies. Arthropods are a source of material for investigation when a human or animal body is in an advanced state of decomposition. Various chemical air pollutants, drugs, xenobiotics and pesticides can accumulate in the bodies of insect larvae. Entomotoxicology often involves examining insect larvae that have introduced to their metabolism various kinds of pharmaceuticals taken by people when they were alive. Chemical compounds which can cause death affect the development rate of arthropods living on corpses, delay colonization of insects by several days, or affect their number. Some compounds act as attractants or repellents and thereby influence how quickly insects appear on the body. Others have a mixed effect on insect development. During the initial development stage of the insect they act as an attractant, but in subsequent stages they slow down its development or act as a repellent. The concentration of chemical compounds accumulated in the bodies of larvae is different than in human tissues. Sometimes insects are better indicators of the presence of chemical compounds than material taken from the internal organs of a dead body. Moreover, the quantity of toxins detected in arthropods differs at different developmental stages. The concentration of a xenobiotic in the body of an insect depends on its type, the stage of development of the insect, and the part of the body it was collected from. Studies have determined that the best place to collect entomotoxicological samples is the internal organs (e.g. the liver). If this is not possible, insects are collected from the head area and the muscles. Due to the low popularity of entomotoxicological testing, this type of evidence often is either not collected at all or collected improperly, preventing valuable information from being obtained. Thus there is a need to verify and standardize methods for safeguarding arthropods for the purposes of entomological toxicology.