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Suction sampling as a significant source of error in molecular analysis of predator diets

  • R.A. King (a1), J.S. Davey (a1), J.R. Bell (a1) (a2), D.S. Read (a1), D.A. Bohan (a2) and W.O.C. Symondson (a1)...


The molecular detection of predation is a fast growing field, allowing highly specific and sensitive detection of prey DNA within the gut contents or faeces of a predator. Like all molecular methods, this technique is prone to potential sources of error that can result in both false positive and false negative results. Here, we test the hypothesis that the use of suction samplers to collect predators from the field for later molecular analysis of predation will lead to high numbers of false positive results. We show that, contrary to previous published work, the use of suction samplers resulted in previously starved predators testing positive for aphid and collembolan DNA, either as a results of ectopic contamination or active predation in the collecting cup/bag. The contradictory evidence for false positive results, across different sampling protocols, sampling devices and different predator-prey systems, highlights the need for experimentation prior to mass field collections of predators to find techniques that minimise the risk of false positives.


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Bell, J.R., Wheater, C.P., Henderson, R. & Cullen, W.R. (2002) Testing the efficiency of suction samplers (G-vacs) on spiders. The effects of increasing nozzle size and suction time. pp. 285290in Toft, S. & Scharff, N. (Eds) European Arachnology 2000. Århus, Denmark, Aarhus University Press.
Bell, J.R., King, R.A., Bohan, D.A. & Symondson, W.O.C. (2010) Spatial co-occurrence networks coupled with molecular analysis of trophic links reveal the spatial dynamics and feeding histories of polyphagous predators. Ecography 33, 6472.
Chapman, E.G., Romero, S.A. & Harwood, J.D. (2010) Maximizing collection and minimizing risk: does vacuum suction sampling increase the likelihood for misinterpretation of food web connections? Molecular Ecology Resources 10, 10231033.
Chen, Y., Giles, K.L., Payton, M.E. & Greenstone, M.H. (2000) Identifying key cereal aphid predators by molecular gut analysis. Molecular Ecology 9, 18871898.
Davey, J.S. (2010) Intraguild predation among generalist predators in winter wheat. PhD thesis, University of Cardiff, Cardiff, UK.
Folmer, O., Black, M., Hoeh, W., Lutz, R. & Vrijenhoek, R. (1994) DNA primers for the amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. Molecular Marine Biology and Biotechnology 3, 294299.
Foltan, P., Sheppard, S., Konvicka, M. & Symondson, W.O.C. (2005) The significance of facultative scavenging in generalist predator nutrition: detecting decayed prey in the guts of predators using PCR. Molecular Ecology 14, 41474158.
Greenstone, M.H., Weber, D.C., Coudron, T.C. & Payton, M.E. (2011) Unnecessary roughness? Testing the hypothesis that predators destined for molecular gut-content analysis must be hand-collected to avoid cross-contamination. Molecular Ecology Resources 11, 286293.
Harwood, J.D. (2008) Are sweep net sampling and pitfall trapping compatible with molecular analysis of predation? Environmental Entomology 37, 990995.
Hebert, L., Darden, S.K., Pedersen, B.V. & Dabelsteen, T. (2011) Increased DNA amplification success of non-invasive genetic samples by successful removal of inhibitors from faecal samples collected in the field. Conservation Genetics Resources 3, 4143.
Hoogendoorn, M. & Heimpel, G.E. (2001) PCR-based gut content analysis of insect predators: using ribosomal ITS-1 fragments from prey to estimate predation frequency. Molecular Ecology 10, 20592067.
Juen, A. & Traugott, M. (2005) Detecting predation and scavenging by DNA gut-content analysis: a case study using a soil insect predator-prey system. Oecologia 142, 344352.
Juen, A. & Traugott, M. (2006) Amplification facilitators and multiplex PCR: tools to overcome PCR-inhibition in DNA-gut-content analysis of soil-living invertebrates. Soil Biology and Biochemistry 38, 18721879.
Juen, A. & Traugott, M. (2007) Revealing species-specific trophic links in soil food webs: molecular identification of scarab predators. Molecular Ecology 16, 15451557.
King, R.A., Read, D.S., Traugott, M. & Symondson, W.O.C. (2008) Molecular analysis of predation: a review of best practice for DNA-based approaches. Molecular Ecology 17, 947963.
King, R.A., Moreno-Ripoll, R., Agustí, N., Shayler, S.P., Bell, J.R., Bohan, D.A. & Symondson, W.O.C. (2011) Multiplex reactions for the molecular detection of predation on pest and non-pest invertebrates in agroecosystems. Molecular Ecology Resources 11, 370373.
Kruse, P.D., Toft, S. & Sunderland, K.D. (2008) Temperature and prey capture: opposite relationships in two predator taxa. Ecological Entomology 33, 305312.
Kuusk, A.K. & Agustí, N. (2008) Group-specific primers for DNA-based detection of springtails (Hexapoda: Collembola) within predator gut contents. Molecular Ecology Resources 8, 678681.
Minitab Inc. (2008) Minitab Statistical Software, Release 15. Available online at (accessed September 2011).
Pons, J. (2006) DNA-based identification of preys from non-destructive, total DNA extractions of predators using arthropod universal primers. Molecular Ecology Notes 6, 623626.
Read, D.S. (2007) Molecular analysis of subterranean detritivore food webs. PhD thesis, University of Cardiff, Cardiff, UK.
Remén, C., Krüger, M. & Cassel-Lundhagen, A. (2010) Successful analysis of gut contents in fungal-feeding oribatid mites by combining body-surface washing and PCR. Soil Biology and Biochemistry 42, 19521957.
Sheppard, S.K., Bell, J., Sunderland, K.D., Fenlon, J., Skervin, D. & Symondson, W.O.C. (2005) Detection of secondary predation by PCR analyses of the gut contents of invertebrate generalist predators. Molecular Ecology 14, 44614468.
Sunderland, K.D., Powell, W. & Symondson, W.O.C. (2005) Populations and communities. pp. 299434in Jervis, M.A. (Ed.) Insects as Natural Enemies: A Practical Perspective. Berlin, Germany, Springer.
Symondson, W.O.C. (2002) Molecular identification of prey in predator diets. Molecular Ecology 11, 627641.
Virant-Doberlet, M., King, R.A., Polajnar, J. & Symondson, W.O.C. (2011) Molecular diagnostics reveal spiders that exploit prey vibrational signals used in sexual communication. Molecular Ecology 20, 22042216.
von Berg, K., Traugott, M., Symondson, W.O.C. & Scheu, S. (2008) The effects of temperature on detection of prey DNA in two species of carabid beetle. Bulletin of Entomological Research 98, 263269.
Wheater, C.P., Bell, J.R. & Cook, P.A. (2011) Practical Field Ecology: A Project Guide. London, UK, Wiley-Blackwell.
Wootton, J.T. & Emmerson, M. (2005) Measurement of interaction strength in nature. Annual Review of Ecology Evolution and Systematics 36, 419444.


Suction sampling as a significant source of error in molecular analysis of predator diets

  • R.A. King (a1), J.S. Davey (a1), J.R. Bell (a1) (a2), D.S. Read (a1), D.A. Bohan (a2) and W.O.C. Symondson (a1)...


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