Can a PCR assay of aphids caught in‐crop on yellow sticky traps inform field level barley yellow dwarf virus risk assessment?

Abstract

Infection with barley yellow dwarf virus (BYDV), caused by strains of virus belonging to the family Luteovirideae including BYDV‐PAV, can result in significant yield losses in autumn sown cereals following transmission by aphid vectors such as Rhopalosiphum padi (Homoptera: Aphididae) and Sitobion avenae (Homoptera: Aphididae). Spatial and temporal variance in the infectivity of alate populations influences risk to crops from the disease, which is greatest on infection at early crop growth stages. A decision support system (DSS) to guide optimised integration of crop protection strategies through risk assessment would help avoid unnecessary application of synthetic insecticides. This study contributes to the development of a DSS by exploring the viability and relevance of a methodology to detect virus levels in individual aphids trapped in‐crop using yellow sticky traps. Using a reverse transcription polymerase chain reaction assay, the detectability of virus from a BYDV‐PAV‐positive control colony was found not to be reduced by the process of trapping, extraction and cold storage, but did drop significantly after between 3 and 7 days of exposure on trap. This method has potential to contribute to localised risk assessment and guide optimisation of crop protection strategies.