Disentangling arthropod and plant resources consumed by Orius spp. in peach and alfalfa crops by metagenomic analysis

Agricultural intensification is affecting the biological control of insect pests, an important component for sustainable crop production. To understand the changing patterns of insect abundance within an agroecosystem, it is necessary to disentangle the trophic interactions between species, and metabarcoding is an excellent alternative to show them. In the Ebro Basin (NE Iberian Peninsula), agricultural landscapes are composed of a mosaic of crops scattered with natural and semi-natural habitats, where the presence of Orius spp., used as biocontrol agents, is well known. To shed light on their predatory role in this area, a previously developed metabarcoding multi-primer method has been used to study the arthropod and plant most frequently resources consumed by some field-collected Orius, sampled at different dates in a peach and an alfalfa adjacent crop. Their high-throughput sequencing (HTS) analysis showed the consumption of 15 arthropod and 12 plant taxa. Eight of them were consumed by O. laevigatus, six by O. majusculus and 23 by O. niger. The obtained results showed that HTS is a powerful tool in studies of trophic interactions in agroecosystems. Among the detected arthropods, other natural enemies were present, showing a certain degree of intraguild predation, which has been demonstrated by developing a new added strategy in the bioinformatic analysis. Detected plant consumption indicates that Orius forages on several plant species, showing their movement from them to the sampled crops. These plants could have a potential role in attracting or maintaining these predators in both crops in biological control strategies.

Automated summary

The intensification of agriculture has impacted the biological control of insect pests. Metabarcoding analysis has been used to study the trophic interactions between species in an agricultural ecosystem in the Ebro Basin. High-throughput sequencing revealed the consumption of arthropods and plants by Orius spp., indicating their potential role in biological control strategies. The analysis also showed the presence of other natural enemies and intraguild predation. This study demonstrates the power of HTS in understanding trophic interactions in agroecosystems.