Caught in the act: impact of Crematogaster cf. liengmei (Hymenoptera: Formicidae) necrophagous behavior on neonate pigs (Sus scrofa domesticus L.) in the Western Cape Province of South Africa

Abstract

Ants have been documented as part of the entomo-sarcosaprophagous community. They have been known to alter the process of carcass decomposition due to their ability to feed on fly eggs/larvae and create postmortem skin injuries. However, studies on the impact of ants on decomposing carcasses are scarce, especially within the Western Cape Province of South Africa. This study was part of a research project that utilized two ( 2) neonate pig carcasses in each month of the year to establish baseline data on the insect species associated with decomposing carcasses in the Western Cape Province of South Africa. In the early spring (September 2020), mid-autumn (May 2021), and mid-winter (July 2021) trials respectively, several individuals of Crematogaster cf. liengmei colonized the pig carcasses shortly after deployment. There, they fed on the flesh of the carcasses and further inflicted bite marks and conspicuous post-mortem skin lesions. Following the reduction in the presence of Crematogaster cf. liengmei specifically in the mid-winter trial, non-vital bleeding was observed as a consequence of the skin lesions. In the early spring, mid-and& late autumn (May 2021), and early (June 2021) and& mid-winter trials respectively, Crematogaster cf. liengmei prevented the formation of large maggot masses, principally through the predation of fly eggs, larvae, and adults. The observations recorded in this study are of considerable importance in forensic investigations as the effect of the necrophagous behaviour of Crematogaster cf. liengmei on decomposing remains can be misinterpreted by inexperienced investigators during crime scene investigations and may alter post-mortem interval estimations.

Parasitic and predatory behavior of Alysia manducator (Hymenoptera: Braconidae) on blow fly larvae feeding on an adult pig carcass in the Western Cape Province of South Africa: preliminary observations and forensic implications

“…This study is part of an ongoing winter carrion decomposition and insect successional study within the area of Table Mountain National Park, adjacent to the University of Cape Town Upper Campus, Rondebosch, South Africa (S33°57.682ʹ; E018°27.301ʹ). The Table Mountain National Park is characterized by a rocky terrain situated on the Cape Peninsula, a mountainous region located at the south-western tip of the African continent [ 5 , 31 ]. The Park is dominated by Mediterranean-like shrubland called fynbos—part of the Cape Floristic Kingdom—which is prone to fire [ 5 , 32 ].…”

“…The Table Mountain National Park is characterized by a rocky terrain situated on the Cape Peninsula, a mountainous region located at the south-western tip of the African continent [ 5 , 31 ]. The Park is dominated by Mediterranean-like shrubland called fynbos—part of the Cape Floristic Kingdom—which is prone to fire [ 5 , 32 ]. The park harbors 2285 plant species of which 90 are endemic [ 5 , 32 ].…”

“…The Park is dominated by Mediterranean-like shrubland called fynbos—part of the Cape Floristic Kingdom—which is prone to fire [ 5 , 32 ]. The park harbors 2285 plant species of which 90 are endemic [ 5 , 32 ]. Pockets of invasive alien vegetation exist, dominated by Acacia , Pinus , and Hakea species [ 5 , 32 ].…”

“…The park harbors 2285 plant species of which 90 are endemic [ 5 , 32 ]. Pockets of invasive alien vegetation exist, dominated by Acacia , Pinus , and Hakea species [ 5 , 32 ].…”

“…The forensic importance of the order Hymenoptera has recently begun to attract the attention of forensic entomologists. This order comprises insects such as ants which have been documented to not only prey on immature and adult stages of other carrion-associated insects, but also inflict injuries, cause hemorrhage, and prevent fly landing and oviposition on vertebrate remains in various parts of the world [ 4 , 5 ]. Another interesting insect group within this order is that of the wasps.…”