Behavioral and Electrophysiological Responses of the Fringed Larder Beetle Dermestes frischii to the Smell of a Cadaver at Different Decomposition Stages

Abstract

A cadaver is colonized by a wide diversity of necrophagous insects. It is well documented that Dipterans are attracted by the volatile organic compounds (VOCs) released by a corpse during the first minutes following death. Coleopterans are known to be attracted by highly decomposed cadavers, but have received less attention regarding the olfaction-based mechanisms underlying these interactions. In the present study, we impregnated gauzes with VOCs collected from each decomposition stage of dead rats: fresh, bloated, active, and advanced decay. We collected the VOCs released by the gauze and confirmed what was previously know from the literature: the decomposition stages are associated with contrasting chemical profiles. We exposed Dermestes frischii Kugelann (Coleoptera: Dermestidae) male and female antennae to the same gauzes and found that stronger electrical responses were recorded when using the smell of the advanced decay stage. Finally, we performed two choices behavioral assays. Females showed no preference for the four decomposition stages, while males were attracted by the smell associated with active and advanced decay stages. These results suggest that specific VOCs released by a decaying body guide necrophagous coleopterans to their feeding site. Whether D. frischii males release pheromones to attract females remains to be tested.

The smell of death. State-of-the-art and future research directions

“…They detected VOCs only from the advanced phase, but none of the decomposition stages elicited their behavioral reaction. These data support the idea that females only react to the cadaver odor when males occur on the remains and emanate pheromones that attract the opposite sex ( Martin et al, 2020a , b ). When evaluating the preference of Nicrophorus vespilloides , gravid beetles are attracted more to the fresh mouse carcass than the older carcass.…”

“…However, the dog breed is still an essential factor for some trainers, but on the other hand, greater emphasis is placed on temperament and the ability to collaborate with humans. From the results of a survey by Martin et al (2020a , b) , according to handlers’ responses, agility and stamina are also essential. However, the length of fur, size of the dog, or percentage of muscle mass is not considered necessary in selection ( Martin et al, 2020a , b ).…”

“…From the results of a survey by Martin et al (2020a , b) , according to handlers’ responses, agility and stamina are also essential. However, the length of fur, size of the dog, or percentage of muscle mass is not considered necessary in selection ( Martin et al, 2020a , b ). Many studies recognize a dog’s motivation, high level of intelligence, and obedience, yet independent when working off-leash as a determinant of cadaver search success ( La Toya et al, 2017 ).…”

The Attraction of the Dung Beetle Anoplotrupes stercorosus (Coleoptera: Geotrupidae) to Volatiles from Vertebrate Cadavers

“…This stage is also characterized by the opening of the body caused by the overpressure of microbial gases and of orifices formed by the feeding processes of insects and vertebrate scavengers. Consequently, the leakage of body fluids and the enhanced emission of VOCs increasingly attract further carrion-feeding insect taxa, such as burying beetles (Coleoptera: Silphidae) [ 10 ] and hide beetles (Coleoptera: Dermestidae) [ 18 , 19 ], until the advanced decay stage and even until the final stage of decomposition, when only dry material remains.…”

Volabolomic Fingerprinting for Post-Mortem Interval Estimation: A Novel Physiological Approach

“…VOCs are the subject of increasing interest in the study of PMIs, and are the target of the DOA database [ 32 ]. It is interesting to note that the best-known molecules characterizing cadaveric effluvium, cadaverine, putrescine, and mercaptans, return a generic putrefactive scent and do not contribute to the characteristic species-specific volaboloma mortis, which is instead a vital clue associated with micro- and macro-scavengers and insects [ 21 , 32 , 42 ]. In fact, high variability among mammals has been demonstrated in the volatile chemical classes of aldehydes, amines, alcohols, and ketones, which characterize the volabolomas of human, dog, pig, and deer carcasses [ 32 ].…”