Monitoring data shows that average pollen beetle numbers rarely exceed the five beetles/plant threshold, yet one-fifth of rape growers sprayed their crops in 2012. It’s a case of a perceived risk and cheap insurance in many situations, says Steve Ellis of Adas. He worries that it may compound insecticide resistance. “It’s not surprising that many growers are using a pyrethoid insecticide such as lambda-cyhalothrin to control pollen beetle when the science behind spraying thresholds has been questionable. “We cannot find […]