Entomological signatures in honey: an environmental DNA metabarcoding approach can disclose information on plant-sucking insects in agricultural and forest landscapes

Abstract

Honeydew produced from the excretion of plant-sucking insects (order Hemiptera) is a carbohydrate-rich material that is foraged by honey bees to integrate their diets. In this study, we used DNA extracted from honey as a source of environmental DNA to disclose its entomological signature determined by honeydew producing Hemiptera that was recovered not only from honeydew honey but also from blossom honey. We designed PCR primers that amplified a fragment of mitochondrial cytochrome c oxidase subunit 1 (COI) gene of Hemiptera species using DNA isolated from unifloral, polyfloral and honeydew honeys. Ion Torrent next generation sequencing metabarcoding data analysis assigned Hemiptera species using a customized bioinformatic pipeline. The forest honeydew honeys reported the presence of high abundance of Cinara pectinatae DNA, confirming their silver fir forest origin. In all other honeys, most of the sequenced reads were from the planthopper Metcalfa pruinosa for which it was possible to evaluate the frequency of different mitotypes. Aphids of other species were identified from honeys of different geographical and botanical origins. This unique entomological signature derived by environmental DNA contained in honey opens new applications for honey authentication and to disclose and monitor the ecology of plant-sucking insects in agricultural and forest landscapes.

Food authentication in real life: How to link nontargeted approaches with routine analytics?

“…Generally, NGS-based detection methods for the authentication of plant foods have been developed, for example for the identification of spices and herbs [56][57][58]. In addition, there are methods for detecting counterfeit honey, which can be used to analyze plant, geographical and insect sources [59,60], and to identify different animal species in meat [61,62], fish [63,64], and dairy products [65]. Other NGS applications focus on the analysis of microorganisms for pathogenic reasons, such as the detection of noroviruses [66] or Salmonella [67,68], but also due to their technological influences, for example during fermentation processes [69,70].…”

Shotgun metagenomics of honey DNA: Evaluation of a methodological approach to describe a multi-kingdom honey bee derived environmental DNA signature

“…derived from pollen) has been used to evaluate honey bee foraging behavior and the botanical composition for authentication [ 15 – 18 ]. Information from plant-sucking insects producing honeydew can be recovered in honey as honey bees routinely collect this sweet material in which the producer hemipters leave their DNA traces [ 19 ]. Other DNA traces left in the honey have been used to identify the bee species and the honey bee subspecies that produced it [ 17 , 20 – 22 ].…”

Plant-animal interactions in the era of environmental DNA (eDNA) – a review

“…In particular, eDNA metabarcoding of honey samples has been demonstrated to detect more taxa than conventional methods, where species-specificity (i.e., identification of generalists and specialists), foraging activity, and complex interactions are analysed rapidly and costeffectively (Hawkins et al, 2015;De Vere et al, 2017). Interestingly, eDNA from honey samples can also help to identify other entomological signatures within forests or agricultural fields, such as those from plantsucking insects whose "honeydew" droplets are incorporated in honey reserves (Utzeri et al, 2018). Bovo et al (2018) further shows the utility of eDNA tools to understand the micro-ecosystem within honey bee colonies by detecting the eDNA signals from five distinct groups (i.e., arthropods, plants, fungi, bacteria, viruses).…”