Molecular characterization of aphid and their mutualistic and antagonistic interactions with co-occurring herbivore in country bean

The bean aphid is a serious pest due to its ability to drain plant sap and spread viruses and controlling it remains challenging in Bangladesh. Ants are known to establish antagonistic and mutualistic interactions with honeydew-producing sucking pests, and their potential varies with the presence of different cooccurring herbivores. This study aims to infer the role that such interactions play in the population dynamics of ants, ladybird beetles, and aphids in country beans in a multilayered correspondence toward developing an effective biocontrol strategy. The molecular characterization of aphids was performed via the use of the cytochrome oxidase subunit-1 gene of mtDNA along with a taxonomic study of ants. The seven treatments (T1 to T7) included periodic culture and mass release of the ladybird beetle (LBB), which induced ants and aphids. Two subspecies of bean aphids, namely, Aphis fabae fabae (Scopoli, 1763) and Aphis fabae cirsiiacanthoidis (Scopoli 1763), were identified in reference to the GenBank accessions OQ892174-OQ892178 and OQ892199-OQ89220. This is the first sequencing of aphid colonies in Bangladesh, which identified two subspecies of black bean aphids. Among the identified ants, Tapinoma simrothi (Emery, 1925) and Monomorium libanicum (Emery, 1925) were found to be effective under both natural and induced LBB conditions. These findings hold promise for the development of sustainable pest management strategies for Bangladesh’s country bean ecosystems.