Incidental observation of bone modification by Crematogaster cf. liengmei (Hymenoptera: Formicidae) in Cape Town, South Africa.

Abstract

Different taxa of insects have been reported to modify the skeletal remains of vertebrates during feeding or the creation of their larval and pupal chambers. Anecdotal reports on the modification of skeletal remains by ants exist but are rare. In this paper, a case of modification of bone due to the feeding activity of the ant, Crematogaster cf. liengmei (Hymenoptera: Formicidae), is reported. In November 2022, a bone was encountered incidentally in the vicinity of the Table Mountain National Park. The bone had been colonized by several individuals of Crematogaster cf. liengmei. Several ants were observed feeding on and removing bone particles and soft tissue remnants. A closer observation revealed striae/furrows on the epiphyseal ends of the bone. A 60-kg pig cadaver used in a winter decomposition trial in the same area was similarly colonized by this ant species, resulting in soft-tissue modification. Due to the similarity in the striae/furrows observed on the bone and the bitemarks inflicted by the ants on the right ear of the pig cadaver in the vicinity, it was concluded that the striae/furrows seen on the bone were created by the ants. Our observations show that Crematogaster cf. liengmei is an important taphonomic bio-agent that can contribute to the modification of skeletal remains in terrestrial environments.