Flight capabilities and feeding habits of silphine beetles: are flightless species really “carrion beetles”

• Published in: Ecological research Vol. 22; no. 2; pp. 237 - 241
• Main Authors: Ikeda, Hiroshi, Kubota, Kohei, Kagaya, Takashi, Abe, Toshio
• Format: Journal Article
• Language: English
• Published: Tokyo Tokyo : Springer-Verlag 01.03.2007; Springer‐Verlag; Blackwell Publishing Ltd
• Subjects: Animal behavior; Carnivore; Carnivores; Evolution & development; Feeding; Flight muscle dimorphism; Insects; Isotopes; Muscles; Necrophagous; Silpha; Soil invertebrates; Stable isotopes; δ13C; δ15N; δ¹³C; δ¹⁵N
• ISSN: 0912-3814; 1440-1703
• DOI: 10.1007/s11284-006-0012-1

We determined the flight capabilities and feeding habits of adults of nine silphine beetle species and illustrated their relationship. We examined the silphine beetles for the presence or absence of flight muscles and estimated their feeding habits by comparing the carbon and nitrogen stable isotope ratios for them with those of necrophagous nicrophorine species and carnivorous carabine species. Three species (Silpha longicornis, S. perforata and Phosphuga atrata) completely lacked individuals with flight muscles, and one species (Eusilpha japonica) showed flight muscle dimorphism. Stable isotope analysis suggested that these species were carnivores, mainly feeding on soil invertebrates. Most flight species showed higher isotopic ratios than the flightless species. Some of them have isotopic ratios close to those of the nicrophorine species, suggesting that these species mainly feed on vertebrate carcasses. Flightless silphine species would have limited ability to search for patchy and unpredictable carcass resources. Further studies are necessary to understand the adaptive evolution of flight capability and the feeding habits in this group.