TY - JOUR T1 - Dung feeding in hydrophilid, geotrupid and scarabaeid beetles: Examples of parallel evolution JF - European Journal Of Entomology Y1 - 2004 A1 - Holter, P. SP - 365 EP - 372 KW - COLEOPTERA dung beetle KW - Dung beetles KW - evolution KW - feeding habits KW - Geotrupidae KW - HELMINTH EGGS KW - hydrophilidae KW - Mouthparts KW - particle feeding KW - Scarabaeidae AB - The maximum size of ingested ball-shaped particles was determined in three species of adult dung feeding beetle: Anoplotrupes (Geotrupes) stercorosus and Geotrupes spiniger (Geotrupidae, Geotrupinae) and Sphaeridium lunatum (Hydrophilidae, Sphaeridiinae). Maximum diameters were 40-65 mum, 60-75 mum and 16-19 mum in A. stercorosus, G. spiniger and S. lunatum, respectively, and it was concluded that these beetles feed in the same way as found in previous studies on coprophagous scarabaeids (Scarabaeinae and Aphodiinae). Coarse particles, mainly indigestible plant fragments, are rejected by an unknown filtering mechanism, and only very small particles are actually ingested. The two geotrupids, however, tolerate somewhat larger particles than do scarabaeines of similar size. This may reflect a lower degree of specialisation towards dung feeding in the geotrupids than in the scarabaeines. In several ways, the mouthparts of the coprophagous Scarabaeidae, Geotrupidae and Hydrophilidae show essentially the same morphological modifications that must be adaptations for dung feeding. For the hydrophilid (Sphaeridium), such modifications are described for the first time. They include asymmetric mandibular molars (right convex, left concave), fitting exactly into each other, with highly specialised surfaces that may concentrate the food prior to ingestion by squeezing fluid out of it. Other examples are the conjunctives (scarabaeids and geotrupids) or similar structures (the hydrophilid) and the large, hairy, pad-like distal lobes of the maxillar galeae. Provided that current views on the evolutionary history of these beetles are correct, dung feeding has arisen independently in the Scarabaeidae, Geotrupidae and Hydrophilidae. If so, the feeding on very small particles and the concomitant modifications of mouthparts in these three groups must be results of parallel evolution. VL - 101 SN - 1210-5759 UR - ://000224407300003 N1 - digital disease ecology, parasite transmission, scarbaeinae, ecological function ER - TY - JOUR T1 - Are ball-rolling (Scarabaeini, Gymnopleurini, Sisyphini) and tunnelling scarabaeine dung beetles equally choosy about the size of ingested dung particles? JF - Ecological Entomology Y1 - 2005 A1 - Holter, P. A1 - Scholtz, Clarke H. SP - 700 EP - 705 KW - Ball-rollers KW - Dung beetles KW - food exploitation KW - particle feeding KW - rollers KW - Scarabaeidae KW - Scarabaeinae KW - telecoprids AB - 1. The maximum size of ingested particles was determined in 11 species of ball-rolling, adult dung beetle (Scarabaeidae: Scarabaeinae) by mixing small latex or glass balls of known diameter into their food. The tribes Scarabaeini, Gymnopleurini, and Sisyphini (four, four, and three species respec- tively) were represented, with mean body sizes ranging from 0.33 to 4.0 g fresh weight. 2. Only particles with maximum diameters of 4–85 mm were ingested. Hence rollers, like other known beetles feeding on fresh dung, filter out larger, indiges- tible plant fragments and confine ingestion to small particles of higher nutritional value. 3. The maximum diameter of ingested particles increased significantly with body weight, whereas taxon (tribe) had no additional effect. Because big rollers accept larger particles than do tunnellers (which make dung stores for feeding and breeding in the soil immediately below the pat) of similar weight, the slope of the diameter-against-weight regression for rollers was significantly higher than that found earlier for tunnellers. 4. An explanation could be that a typical food ball made by a roller is con- siderably smaller than the amount of dung available to a feeding tunneller of the same size. If the roller were as choosy about particle size as the tunneller, it might not get enough food. This applies to large rollers in particular because their food balls contain a higher proportion of coarse fibres than those made by small species. VL - 30 ER -