Submitted to: Molecular Ecology Resources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 2, 2011
Publication Date: January 24, 2012
Citation: Greenstone, M.H., Weber, D.C., Hu, J.S., Coudron, T.A., Payton, M. 2012. Removing external DNA decontamination from arthropod predators destined for molecular gut-content analysis. Molecular Ecology Resources. 12:464-469.
Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Field and laboratory experiments have demonstrated that mass-collection methods, such as sweep-netting, vacuum sampling, and foliage beating, can lead to contamination of fed predators with non-target DNA, thereby compromising resultant gut-content data. We deliberately contaminated immature Coleomegilla maculata and Podisus maculiventris that had been fed larvae of Leptinotarsa decemlineata by topically applying homogenate of the alternate prey L. juncta. We then attempted to remove contaminating DNA by soaking in ethanol or bleach. A 40-min soak with rotation in 80% EtOH did not reliably reduce external DNA contamination. Identical treatment with 2.5 % commercial bleach removed externally contaminating DNA without affecting the detectability of the target prey DNA in the gut. Use of this bleaching protocol, perhaps with minor modifications depending on the predator-prey system, should reliably eliminate external DNA contamination, freeing investigators to use conventional methods for mass collection of arthropod predators for molecular gut-content analysis