Molecular Ecology Resources (2018) 18, 966-973

Stefaniya Kamenova, Rebecca Mayer, Oskar R. Rubbmark, Eric Coissac, Manuel Plantegenest and Michael Traugott (2018)
Comparing three types of dietary samples for prey DNA decay in an insect generalist predator
Molecular Ecology Resources 18 (5), 966-973
Abstract: The rapidly growing field of molecular diet analysis is becoming increasingly popular among ecologists, especially when investigating methodologically challenging groups, such as invertebrate generalist predators. Prey DNA detection success is known to be affected by multiple factors; however, the type of dietary sample has rarely been considered. Here, we address this knowledge gap by comparing prey DNA detection success from three types of dietary samples. In a controlled feeding experiment, using the carabid beetle Pterostichus melanarius as a model predator, we collected regurgitates, faeces and whole consumers (including their gut contents) at different time points postfeeding. All dietary samples were analysed using multiplex PCR, targeting three different length DNA fragments (128, 332 and 612 bp). Our results show that both the type of dietary sample and the size of the DNA fragment contribute to a significant part of the variation found in the detectability of prey DNA. Specifically, we observed that in both regurgitates and whole consumers, prey DNA was detectable significantly longer for all fragment sizes than for faeces. Based on these observations, we conclude that prey DNA detected from regurgitates and whole consumers DNA extracts are comparable, whereas prey DNA detected from faeces, though still sufficiently reliable for ecological studies, will not be directly comparable to the former. Therefore, regurgitates and faeces constitute a useful, nonlethal source for dietary information that could be applied to field studies in situations when invertebrate predators should not be killed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: English)
Link to article at publishers website
Database assignments for author(s): Michael Traugott

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Pterostichus melanarius (predator)