Tracking Dermestid Beetles to Carrion: A Case Study

Although insects belonging to the order Coleoptera constitute the largestorder in the animal kingdom, there is a noticeable lack of research on beetle activityand behavior. Necrophagous beetles such as dermestids (family: Dermestidae) areearly colonizers of corpses, but little is understood about the speed at which theytravel or the distances they will cover to reach carrion. In this experiment, fourgroups of marked Dermestes maculatus beetles were released at four separatelocations near two Bos taurus (cow) heads (H1 and H2), placed 40 m apart. H1 wasstationed in a riparian forest environment and H2 in a grassland pasture setting. Thetwo groups of beetles released in the grassland pasture setting, at 20 m and 40 maway from H2, reached H2 within 12 hours. The two groups released in the riparianforest, 60 m and 80 m away, reached H2 within 36 hours. Marked beetles were notobserved at the head in the riparian forest environment (H1) until 54 hours hadelapsed, which raises the question as to why beetles would bypass carrion closest tothem in the riparian forest to get to carrion in the grassland pasture. Although beetleactivity was reduced under peak site temperatures, they were active at temperaturesthat exceeded the range of high activity in related studies. This is the first study tothe authors’ knowledge that has released an established colony of D. maculatus in anattempt to determine their rate of travel to decaying remains, as well as the first tomeasure beetle interest in feeding in two separate environments. Determining themaximum speed and distance dermestids may travel to reach corpses may helpinvestigators search for remains and provide important evidence useful inestablishing time since death.