*3.1.5. Biosensors*

Parasitic wasps do offer some advantages to forensic entomologists not yet exploited with necrophagous Diptera, namely in the form of chemical detection of decomposing bodies [43]. Under natural conditions, most species of parasitic wasps rely on chemical cues during foraging to locate potential hosts and their food resources [63]. At least with one species, *Microplitis croceipes* (Braconidae), a wasp that utilizes the larval stages of agricultural pests (Lepidoptera: Noctuidae) as hosts, can be trained through Pavlovian conditioning to associate a wide range of factitious chemicals with food [64, 65]. Odorants common to decomposition of animal tissues, that is, cadaverine and putrescine, have been used to successfully condition adult females, which, in turn, demonstrate foraging behavior in the presence of the odors [66]. Thus far the research is still in its infancy and has not yet been tested in a field setting to determine if *M*. *croceipes* can successfully locate a decomposing corpse emitting odors recog‐ nized by the wasps. For practical use, the parasitoids need to be tractable like has been done with honeybees, *Apis mellifera* (Hymenoptera: Apidae) equipped with GPS or radio signal detection when used as a sniffer system [67]. Other species have not been tested yet to determine how widespread is the ability of parasitic Hymenoptera to be used for the location of decomposing bodies. The technique would be especially valuable for finding concealed remains, such as buried, trapped in secluded locations, or those hidden in artificial containers.
