The use of molecular tools to unravel host-parasitoid-hyperparasitoid interactions

The detection and identification of trophic interactions in biological control can be challenging using conventional rearing and dissection techniques, as visible evidence of these interactions is not always present, and one or more species may be overlooked. This can be particularly problematic in the field, where a number of different parasitoids and hyperparasitoids may exploit the same host, but only one individual will survive and emerge. In addition, common monitoring techniques such as sticky cards, lead to poor quality specimen for precise taxonomic assignments. Molecular techniques can overcome these challenges through detecting trace amounts of DNA belonging to the host, primary parasitoid(s), and hyperparasitoids; thereby allowing the identification of links between different trophic levels, as well as competition within the same trophic level (e.g., competition, intraguild predation). Here we present case studies in different agricultural systems where molecular diagnostic tools have been used to unravel host-parasitoid-hyperparasitoid interactions, and provide insight on the utility of different molecular approaches.