Rising temperatures raise Bruchid risk

Bruchid Beetle are on the move and, with rising temperatures bringing at least two consecutive hot days forecast this week also coinciding with first pod set in many winter bean crops, the risks of damaging egg laying activity has increased significantly.

Mark Bullen of Syngenta advises the company’s BruchidCast system, developed in conjunction with the PGRO, has been on the verge of triggering a high risk warning. ’We are already receiving reports of Bruchid Beetles moving around in bean crops. When temperatures rise above 20’C this week, growers will have to take quick action to disrupt mating activity of the female beetles and prevent them laying eggs on the newly formed pods,’ he warns.

BruchidCast is designed to optimise the timing of insecticide applications by giving up to five-day advance warning of periods of peak pest activity. ’The information also includes a forecast of potential spraying opportunities, which this year are being severely disrupted by persistently strong winds,’ he added. ’Using the forecasts together is a powerful tool to identify when there is increasing risk of pest damage, and when growers may have the chance to intervene.’

Becky Ward of PGRO adds that the early flowering of many bean crops this year, induced by the dry weather, may leave crops exposed to risk of Bruchid Beetle attack for a prolonged period. Growers should take heed of BruchidCast warnings and treat with Hallmark Zeon through the susceptible growth stages, when the system forecasts two consecutive days over 20’C, she advises.

Colonies of Black Bean Aphid have also been reported developing on winter bean crops in the south this week, with continued dry weather favouring pest build-up in already stressed crops. Applications of Aphox should be made when first colonies are seen and aphids are causing damage. This can be tank-mixed with Hallmark Zeon where aphids are a target alongside Bruchid Beetle.