Diet shift in giant Madagascan dung beetle Helictopleurus giganteus (Coleoptera: Scarabaeidae: Scarabaeinae) studied by amplicon metagenomics

Abstract

Dung beetles are important elements in the food webs in Madagascar, where they evolved as consumers of lemur excrements. The anthropogenic pressure reduces lemur populations, which causes dung beetles to shift to other food sources. To assess the diet of giant Madagascan dung beetle Helictopleurus giganteus (Harold), we studied hindgut content of seven specimens from different localities with amplicon metagenomic methods. We found reads of five mammal species, with over 99% of total reads belonging to human and cow. No native Madagascan mammals were detected in the samples. The results suggest the human mediated diet shift in H. giganteus, although they should be interpreted with caution, because unavoidable contaminations may contribute reasonably to the high yield of the cow and human reads.