The sudden arrival of summer temperatures has seen a surge in bruchid Beetle activity, at a time when bean crops are most susceptible to attack. The pest advance warning system, BruchidCast, has predicted successive days of intense beetle sexual activity and egg laying in crops across Southern and Eastern England.
Research by Syngenta and the PGRO has identified that two successive days of temperatures above 20°C will trigger bruchid activity and, if crops have first pods set, the onset of egg laying that will develop into damaging larvae attacks.
Where these conditions occur, Syngenta Technical Manager, Pete Saunders, advocated treatment with Hallmark Zeon to prevent adult egg laying. “Bruchid monitoring has identified the beetles have been around in crops for some weeks. When weather conditions are right, the breeding cycle will kick off,” he warned.
Trials have shown that application using angled nozzles, alternated forward and backward along the spray boom, had proven most effective in targeting beetles within the crop. In particularly tall, dense crops operators should consider increasing water volume to aid coverage throughout the canopy, he added.
Further Syngenta application research this season is evaluating innovative new nozzle technology to optimise bruchid spray treatments in beans.
PGRO Principal Technical Officer, Becky Ward, reported that BruchidCast and the new research-based decision support advice had helped to significantly reduce levels of beetle larvae infestation in recent years.
Even with the extremely high insect pest pressure of summer 2014, beetle damage in beans had remained low across most of the south and east, although there was some increase in crops grown in northern England, she added.
“Results would indicate that major bean quality issues had successfully been avoided where growers had heeded the BruchidCast early warning forecasts to time insecticide treatments and used new improved application techniques,” she said. “But where they didn’t, the level of damage and economic loss was high.”