These dung flies are black in color, and approximately 4–5 mm (0.16–0.20 in) long. They have two translucent wings that contain one dark spot near the tip of each. They look like ants, and often are difficult to identify without a microscope due to their appearance.
The temperature during the larval phase of development impacts growth rates and final body size of Sepsis cynipsea. S. cynipsea grow the best at intermediate temperatures compared to similar species. However, in colder temperatures, S. cynipsea growth rates may increase so that they can reach adulthood before a cold season. Their growth rate also increases with warmer temperatures. At 30 °C (86 °F), it takes approximately 7 days for S. cynipsea flies to mature from eggs to adults. Resource availability, which can vary based on environmental conditions and competition with other species, also has an impact on the size of an adult body. S. cynipsea primarily uses temperature to determine when to enter diapause.
Larger males are more successful at mounting and mating with females, and larger females lay larger clutches of eggs. In populations with greater mean body sizes, sexual selection is stronger compared to populations with smaller body sizes. Once the male and female move into the grass after she lays her eggs, only about 40% of the pairs actually copulate. And when they do, there is evidence to suggest that females get physically injured in the process. The male reproductive organ is spiney, and females are left with scars and have a higher mortality after mating. This genital organ is most likely so armored to make it hard for the females to shake the males off; the male has to spin 180 degrees to get his genital organ out of the female. If a female does not shake the male off, they copulate. The flies then find another dung site 2–4 days later to repeat the process. This results in approximately six generations to progress during each breeding season.
There are high levels of genetic variability between flies, especially related to form. The heritability of these morphological traits ranges between 0.33 and 0.90 for males but is lower for females. Male Sepsis cynipsea flies are smaller than females for all traits except for the width of the fore femur. Body size and male leg features are selected for, so evolution works on these traits and contributes to sexual dimorphism.
Blanckenhorn, W. (1997). "Altitudinal life history variation in the dung flies Scathophaga stercoraria and Sepsis cynipsea". Oecologia. 109: 342–352. doi:10.1007/s004420050092. /wiki/Doi_(identifier)
Rohner, P. T., Bächli, G. , Pollini Paltrinieri, L. , Duelli, P. , Obrist, M. K., Jochmann, R. and Blanckenhorn, W. U. (2015), Distribution, diversity gradients and Rapoport's elevational rule in the black scavenger flies of the Swiss Alps (Diptera: Sepsidae). Insect Conserv Divers, 8: 367-376. doi:10.1111/icad.12114
Blanckenhorn, W. (1997). "Altitudinal life history variation in the dung flies Scathophaga stercoraria and Sepsis cynipsea". Oecologia. 109: 342–352. doi:10.1007/s004420050092. /wiki/Doi_(identifier)
Wolf U. Blanckenhorn, David J. Hosken, Oliver Y. Martin, Constanze Reim, Yvonne Teuschl, Paul I. Ward, The costs of copulating in the dung fly Sepsis cynipsea, Behavioral Ecology, Volume 13, Issue 3, May 2002, Pages 353–358, https://doi.org/10.1093/beheco/13.3.353 https://doi.org/10.1093/beheco/13.3.353
Blanckenhorn, Morf; Mühlhäuser, Reusch (1999). "Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea". Journal of Evolutionary Biology. 12 (3): 563–576. doi:10.1046/j.1420-9101.1999.00050.x. https://doi.org/10.1046%2Fj.1420-9101.1999.00050.x
Blanckenhorn, Morf; Mühlhäuser, Reusch (1999). "Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea". Journal of Evolutionary Biology. 12 (3): 563–576. doi:10.1046/j.1420-9101.1999.00050.x. https://doi.org/10.1046%2Fj.1420-9101.1999.00050.x
Blanckenhorn, W. (1997). "Altitudinal life history variation in the dung flies Scathophaga stercoraria and Sepsis cynipsea". Oecologia. 109: 342–352. doi:10.1007/s004420050092. /wiki/Doi_(identifier)
Blanckenhorn, W. (1997). "Altitudinal life history variation in the dung flies Scathophaga stercoraria and Sepsis cynipsea". Oecologia. 109: 342–352. doi:10.1007/s004420050092. /wiki/Doi_(identifier)
Blanckenhorn, Morf; Mühlhäuser, Reusch (1999). "Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea". Journal of Evolutionary Biology. 12 (3): 563–576. doi:10.1046/j.1420-9101.1999.00050.x. https://doi.org/10.1046%2Fj.1420-9101.1999.00050.x
Blanckenhorn, Morf; Mühlhäuser, Reusch (1999). "Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea". Journal of Evolutionary Biology. 12 (3): 563–576. doi:10.1046/j.1420-9101.1999.00050.x. https://doi.org/10.1046%2Fj.1420-9101.1999.00050.x
Rohner, P. T., Bächli, G. , Pollini Paltrinieri, L. , Duelli, P. , Obrist, M. K., Jochmann, R. and Blanckenhorn, W. U. (2015), Distribution, diversity gradients and Rapoport's elevational rule in the black scavenger flies of the Swiss Alps (Diptera: Sepsidae). Insect Conserv Divers, 8: 367-376. doi:10.1111/icad.12114
Rohner, P. T., Bächli, G. , Pollini Paltrinieri, L. , Duelli, P. , Obrist, M. K., Jochmann, R. and Blanckenhorn, W. U. (2015), Distribution, diversity gradients and Rapoport's elevational rule in the black scavenger flies of the Swiss Alps (Diptera: Sepsidae). Insect Conserv Divers, 8: 367-376. doi:10.1111/icad.12114
Rohner, P. T., Bächli, G. , Pollini Paltrinieri, L. , Duelli, P. , Obrist, M. K., Jochmann, R. and Blanckenhorn, W. U. (2015), Distribution, diversity gradients and Rapoport's elevational rule in the black scavenger flies of the Swiss Alps (Diptera: Sepsidae). Insect Conserv Divers, 8: 367-376. doi:10.1111/icad.12114
Rohner, P. T., Bächli, G. , Pollini Paltrinieri, L. , Duelli, P. , Obrist, M. K., Jochmann, R. and Blanckenhorn, W. U. (2015), Distribution, diversity gradients and Rapoport's elevational rule in the black scavenger flies of the Swiss Alps (Diptera: Sepsidae). Insect Conserv Divers, 8: 367-376. doi:10.1111/icad.12114
Blanckenhorn, W. U. (1998). Altitudinal differentiation in the diapause response of two species of dung flies. Ecological Entomology 23, 1-8. /wiki/Diapause
Blanckenhorn, W. U. (1999). Different growth responses to temperature and resource limitation in three fly species with similar life histories. Evolutionary Ecology 13: 395-409
Blanckenhorn, W. U. (1999). Different growth responses to temperature and resource limitation in three fly species with similar life histories. Evolutionary Ecology 13: 395-409
Blanckenhorn, W. U. (1999). Different growth responses to temperature and resource limitation in three fly species with similar life histories. Evolutionary Ecology 13: 395-409
Blanckenhorn, Morf; Mühlhäuser, Reusch (1999). "Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea". Journal of Evolutionary Biology. 12 (3): 563–576. doi:10.1046/j.1420-9101.1999.00050.x. https://doi.org/10.1046%2Fj.1420-9101.1999.00050.x
Blanckenhorn, Morf; Mühlhäuser, Reusch (1999). "Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea". Journal of Evolutionary Biology. 12 (3): 563–576. doi:10.1046/j.1420-9101.1999.00050.x. https://doi.org/10.1046%2Fj.1420-9101.1999.00050.x
Blanckenhorn, W. U. (1998). Altitudinal differentiation in the diapause response of two species of dung flies. Ecological Entomology 23, 1-8. /wiki/Diapause
Rohner, P. T., Bächli, G. , Pollini Paltrinieri, L. , Duelli, P. , Obrist, M. K., Jochmann, R. and Blanckenhorn, W. U. (2015), Distribution, diversity gradients and Rapoport's elevational rule in the black scavenger flies of the Swiss Alps (Diptera: Sepsidae). Insect Conserv Divers, 8: 367-376. doi:10.1111/icad.12114
Blanckenhorn, W. (1997). "Altitudinal life history variation in the dung flies Scathophaga stercoraria and Sepsis cynipsea". Oecologia. 109: 342–352. doi:10.1007/s004420050092. /wiki/Doi_(identifier)
Teuschl, Y; Blanckenhorn, Wolf U (2007). The reluctant fly: what makes Sepsis cynipsea females willing to copulate? Animal Behaviour, 73(1):85-97.
Parker, G..A. (1972). Reproductive Behaviour of Sepsis Cynipsea (L.) (Diptera: Sepsidae) I. a Preliminary Analysis of the Reproductive Strategy and Its Associated Behaviour Patterns, Behaviour, 41(1-2), 172-205. doi: https://doi.org/10.1163/156853972X00257 https://doi.org/10.1163/156853972X00257
Blanckenhorn, W. U., Mühlhäuser, C. , Morf, C. , Reusch, T. and Reuter, M. (2000), Female Choice, Female Reluctance to Mate and Sexual Selection on Body Size in the Dung Fly Sepsis cynipsea. Ethology, 106: 577-593. doi:10.1046/j.1439-0310.2000.00573.x
Blanckenhorn, W. U., Mühlhäuser, C. , Morf, C. , Reusch, T. and Reuter, M. (2000), Female Choice, Female Reluctance to Mate and Sexual Selection on Body Size in the Dung Fly Sepsis cynipsea. Ethology, 106: 577-593. doi:10.1046/j.1439-0310.2000.00573.x
Puniamoorthy, N., Su, K., & Meier, R. (2008). Bending for love: losses and gains of sexual dimorphisms are strictly correlated with changes in the mounting position of sepsid flies (Sepsidae: Diptera). BMC Evolutionary Biology, 8(1), 155. https://doi.org/10.1186/1471-2148-8-155 https://doi.org/10.1186/1471-2148-8-155
Teuschl, Y; Blanckenhorn, Wolf U (2007). The reluctant fly: what makes Sepsis cynipsea females willing to copulate? Animal Behaviour, 73(1):85-97.
Teuschl, Y; Blanckenhorn, Wolf U (2007). The reluctant fly: what makes Sepsis cynipsea females willing to copulate? Animal Behaviour, 73(1):85-97.
Blanckenhorn, W. U. (1999). Different growth responses to temperature and resource limitation in three fly species with similar life histories. Evolutionary Ecology 13: 395-409
Blanckenhorn, W. U. (1999). Different growth responses to temperature and resource limitation in three fly species with similar life histories. Evolutionary Ecology 13: 395-409
Blanckenhorn, W. U., Mühlhäuser, C. , Morf, C. , Reusch, T. and Reuter, M. (2000), Female Choice, Female Reluctance to Mate and Sexual Selection on Body Size in the Dung Fly Sepsis cynipsea. Ethology, 106: 577-593. doi:10.1046/j.1439-0310.2000.00573.x
Parker, G..A. (1972). Reproductive Behaviour of Sepsis Cynipsea (L.) (Diptera: Sepsidae) I. a Preliminary Analysis of the Reproductive Strategy and Its Associated Behaviour Patterns, Behaviour, 41(1-2), 172-205. doi: https://doi.org/10.1163/156853972X00257 https://doi.org/10.1163/156853972X00257
Blanckenhorn, W. U., Mühlhäuser, C. , Morf, C. , Reusch, T. and Reuter, M. (2000), Female Choice, Female Reluctance to Mate and Sexual Selection on Body Size in the Dung Fly Sepsis cynipsea. Ethology, 106: 577-593. doi:10.1046/j.1439-0310.2000.00573.x
Teuschl, Y; Blanckenhorn, Wolf U (2007). The reluctant fly: what makes Sepsis cynipsea females willing to copulate? Animal Behaviour, 73(1):85-97.
Blanckenhorn, W. U., Mühlhäuser, C. , Morf, C. , Reusch, T. and Reuter, M. (2000), Female Choice, Female Reluctance to Mate and Sexual Selection on Body Size in the Dung Fly Sepsis cynipsea. Ethology, 106: 577-593. doi:10.1046/j.1439-0310.2000.00573.x
Wolf U. Blanckenhorn, David J. Hosken, Oliver Y. Martin, Constanze Reim, Yvonne Teuschl, Paul I. Ward, The costs of copulating in the dung fly Sepsis cynipsea, Behavioral Ecology, Volume 13, Issue 3, May 2002, Pages 353–358, https://doi.org/10.1093/beheco/13.3.353 https://doi.org/10.1093/beheco/13.3.353
Blanckenhorn, Morf; Mühlhäuser, Reusch (1999). "Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea". Journal of Evolutionary Biology. 12 (3): 563–576. doi:10.1046/j.1420-9101.1999.00050.x. https://doi.org/10.1046%2Fj.1420-9101.1999.00050.x
Blanckenhorn, Morf; Mühlhäuser, Reusch (1999). "Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea". Journal of Evolutionary Biology. 12 (3): 563–576. doi:10.1046/j.1420-9101.1999.00050.x. https://doi.org/10.1046%2Fj.1420-9101.1999.00050.x
Teuschl, Y; Blanckenhorn, Wolf U (2007). The reluctant fly: what makes Sepsis cynipsea females willing to copulate? Animal Behaviour, 73(1):85-97.
Wolf U. Blanckenhorn, David J. Hosken, Oliver Y. Martin, Constanze Reim, Yvonne Teuschl, Paul I. Ward, The costs of copulating in the dung fly Sepsis cynipsea, Behavioral Ecology, Volume 13, Issue 3, May 2002, Pages 353–358, https://doi.org/10.1093/beheco/13.3.353 https://doi.org/10.1093/beheco/13.3.353
Wolf U. Blanckenhorn, David J. Hosken, Oliver Y. Martin, Constanze Reim, Yvonne Teuschl, Paul I. Ward, The costs of copulating in the dung fly Sepsis cynipsea, Behavioral Ecology, Volume 13, Issue 3, May 2002, Pages 353–358, https://doi.org/10.1093/beheco/13.3.353 https://doi.org/10.1093/beheco/13.3.353
Teuschl, Y; Blanckenhorn, Wolf U (2007). The reluctant fly: what makes Sepsis cynipsea females willing to copulate? Animal Behaviour, 73(1):85-97.
Blanckenhorn, Morf; Mühlhäuser, Reusch (1999). "Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea". Journal of Evolutionary Biology. 12 (3): 563–576. doi:10.1046/j.1420-9101.1999.00050.x. https://doi.org/10.1046%2Fj.1420-9101.1999.00050.x
Puniamoorthy, N., Su, K., & Meier, R. (2008). Bending for love: losses and gains of sexual dimorphisms are strictly correlated with changes in the mounting position of sepsid flies (Sepsidae: Diptera). BMC Evolutionary Biology, 8(1), 155. https://doi.org/10.1186/1471-2148-8-155 https://doi.org/10.1186/1471-2148-8-155
Puniamoorthy, N., Su, K., & Meier, R. (2008). Bending for love: losses and gains of sexual dimorphisms are strictly correlated with changes in the mounting position of sepsid flies (Sepsidae: Diptera). BMC Evolutionary Biology, 8(1), 155. https://doi.org/10.1186/1471-2148-8-155 https://doi.org/10.1186/1471-2148-8-155
Puniamoorthy, N., Su, K., & Meier, R. (2008). Bending for love: losses and gains of sexual dimorphisms are strictly correlated with changes in the mounting position of sepsid flies (Sepsidae: Diptera). BMC Evolutionary Biology, 8(1), 155. https://doi.org/10.1186/1471-2148-8-155 https://doi.org/10.1186/1471-2148-8-155
Puniamoorthy, N., Su, K., & Meier, R. (2008). Bending for love: losses and gains of sexual dimorphisms are strictly correlated with changes in the mounting position of sepsid flies (Sepsidae: Diptera). BMC Evolutionary Biology, 8(1), 155. https://doi.org/10.1186/1471-2148-8-155 https://doi.org/10.1186/1471-2148-8-155
Puniamoorthy, N., Su, K., & Meier, R. (2008). Bending for love: losses and gains of sexual dimorphisms are strictly correlated with changes in the mounting position of sepsid flies (Sepsidae: Diptera). BMC Evolutionary Biology, 8(1), 155. https://doi.org/10.1186/1471-2148-8-155 https://doi.org/10.1186/1471-2148-8-155
Zhao, L., Annie, A. S. H., Amrita, S., Yi, S. K. F., & Rudolf, M. (2013). Does better taxon sampling help? A new phylogenetic hypothesis for Sepsidae (Diptera: Cyclorrhapha) based on 50 new taxa and the same old mitochondrial and nuclear markers. Molecular Phylogenetics and Evolution, 69(1), 153–164. https://doi.org/10.1016/j.ympev.2013.05.011 https://doi.org/10.1016/j.ympev.2013.05.011
Giesen, A, Schäfer, MA, Blanckenhorn, WU. Geographic patterns of postzygotic isolation between two closely related widespread dung fly species (Sepsis cynipsea and Sepsis neocynipsea; Diptera: Sepsidae). J Zool Syst Evol Res. 2019; 57: 80– 90. https://doi.org/10.1111/jzs.12239 https://doi.org/10.1111/jzs.12239
Zhao, L., Annie, A. S. H., Amrita, S., Yi, S. K. F., & Rudolf, M. (2013). Does better taxon sampling help? A new phylogenetic hypothesis for Sepsidae (Diptera: Cyclorrhapha) based on 50 new taxa and the same old mitochondrial and nuclear markers. Molecular Phylogenetics and Evolution, 69(1), 153–164. https://doi.org/10.1016/j.ympev.2013.05.011 https://doi.org/10.1016/j.ympev.2013.05.011
Zhao, L., Annie, A. S. H., Amrita, S., Yi, S. K. F., & Rudolf, M. (2013). Does better taxon sampling help? A new phylogenetic hypothesis for Sepsidae (Diptera: Cyclorrhapha) based on 50 new taxa and the same old mitochondrial and nuclear markers. Molecular Phylogenetics and Evolution, 69(1), 153–164. https://doi.org/10.1016/j.ympev.2013.05.011 https://doi.org/10.1016/j.ympev.2013.05.011
Zhao, L., Annie, A. S. H., Amrita, S., Yi, S. K. F., & Rudolf, M. (2013). Does better taxon sampling help? A new phylogenetic hypothesis for Sepsidae (Diptera: Cyclorrhapha) based on 50 new taxa and the same old mitochondrial and nuclear markers. Molecular Phylogenetics and Evolution, 69(1), 153–164. https://doi.org/10.1016/j.ympev.2013.05.011 https://doi.org/10.1016/j.ympev.2013.05.011
Giesen, A, Schäfer, MA, Blanckenhorn, WU. Geographic patterns of postzygotic isolation between two closely related widespread dung fly species (Sepsis cynipsea and Sepsis neocynipsea; Diptera: Sepsidae). J Zool Syst Evol Res. 2019; 57: 80– 90. https://doi.org/10.1111/jzs.12239 https://doi.org/10.1111/jzs.12239
Giesen, A, Schäfer, MA, Blanckenhorn, WU. Geographic patterns of postzygotic isolation between two closely related widespread dung fly species (Sepsis cynipsea and Sepsis neocynipsea; Diptera: Sepsidae). J Zool Syst Evol Res. 2019; 57: 80– 90. https://doi.org/10.1111/jzs.12239 https://doi.org/10.1111/jzs.12239
Giesen, A, Schäfer, MA, Blanckenhorn, WU. Geographic patterns of postzygotic isolation between two closely related widespread dung fly species (Sepsis cynipsea and Sepsis neocynipsea; Diptera: Sepsidae). J Zool Syst Evol Res. 2019; 57: 80– 90. https://doi.org/10.1111/jzs.12239 https://doi.org/10.1111/jzs.12239
Giesen, A, Schäfer, MA, Blanckenhorn, WU. Geographic patterns of postzygotic isolation between two closely related widespread dung fly species (Sepsis cynipsea and Sepsis neocynipsea; Diptera: Sepsidae). J Zool Syst Evol Res. 2019; 57: 80– 90. https://doi.org/10.1111/jzs.12239 https://doi.org/10.1111/jzs.12239
Giesen, A., Blanckenhorn, W. U., & Schäfer, M. A. (2017). Behavioural mechanisms of reproductive isolation between two hybridizing dung fly species. Animal Behaviour, 132, 155–166. https://doi.org/10.1016/j.anbehav.2017.08.008 https://doi.org/10.1016/j.anbehav.2017.08.008
Giesen, A., Blanckenhorn, W. U., & Schäfer, M. A. (2017). Behavioural mechanisms of reproductive isolation between two hybridizing dung fly species. Animal Behaviour, 132, 155–166. https://doi.org/10.1016/j.anbehav.2017.08.008 https://doi.org/10.1016/j.anbehav.2017.08.008
Reusch, T., & Blanckenhorn, W. U. (1998). Quantitative genetics of the dung fly Sepsis cynipsea: Cheverud’s conjecture revisited. Heredity, 81(1), 111–119. https://doi.org/10.1046/j.1365-2540.1998.00368.x https://doi.org/10.1046/j.1365-2540.1998.00368.x
Reusch, T., & Blanckenhorn, W. U. (1998). Quantitative genetics of the dung fly Sepsis cynipsea: Cheverud’s conjecture revisited. Heredity, 81(1), 111–119. https://doi.org/10.1046/j.1365-2540.1998.00368.x https://doi.org/10.1046/j.1365-2540.1998.00368.x