New insights into the diets of seven hymenopteran species using trnL metabarcoding in a Malaysian tropical forest reserve

Historically, wasps were considered merely flower visitors but are now recognized as playing a significant role in interactions with flowering plants. Recent studies indicate that certain wasp families exhibit pollen transport capacity and plant fidelity comparable to some well-known bee pollinators. This study examined the diet on 19 samples comprised of seven hymenopteran species (wasps; Polistes sp., Paramblynotus sp., Polybioides sp., and Auplopus sp., and bees; Tetrigona apicalis, Apis cerana and Nomia strigata) collected from a model site, the protected primary forest of Tengku Hassanal Wildlife Reserve (THWR), Pahang, Malaysia. All 19 hymenopteran samples were subjected to metabarcoding analysis of trnL utilising the Illumina MiSeq platform. Through bioinformatic analyses, the single phylum Streptophyta, comprising 44 known families and 100 known species, was detected, and 15 top species were discussed. Fabaceae (11.45%) emerges as the most predominant plant family recorded, followed by Gesneriaceae (11.03%), Podostemaceae (10.18%), Asteraceae (8.99%), and Poaceae (6.43%). Rachunia cymbiformis (Gesneriaceae), Polypleurum chinense (Podostemaceae), Taraxacum platycarpum (Asteraceae), Chusquea sp. (Poaceae), and Lycoris sp. 1 (Amaryllidaceae) are the top five species being consumed, with 10.90%, 10.18%, 8.14%, 5.84%, and 4.57%, respectively. Notably, Dipterocarpus turbinatus (Dipterocarpaceae), listed as Vulnerable by the IUCN, was recorded in four hymenopteran species. Molecular evidence also revealed that several forest trees and crop species from nearby villages were foraged by both wasps and bees. The data would be beneficial for relevant authorities in formulating a management and conservation strategy for the forest.