All but four of the UK weather stations (79 of 83) monitored by the Bayer Pollen Beetle Predictor have had weather conducive to suggest pollen beetle migration has started. Conditions remain moderate for most of the UK, except some parts of eastern England (Thetford, Bury St Edmunds, Halstead and Harlow) which are now experiencing good conditions for pollen beetle migration.
With the slow start to spring growth this season, many crops are looking notably uneven, with green buds evident in some crops in the east. Rothamsted researcher Dr Sam Cook says that the cold weather has kept migrations at bay so far, but that growers should remain mindful that the major migration events are still to come.
“Spring vigour is really kicking in now, with crops beginning to make up for the slow start. Growers need to continue to monitor the pollen beetle predictor tool and hope that the crop continues to stay one step ahead of the beetles.”
For now forecasts suggest that temperatures will remain lower than the 15°C required for beetles to migrate to crops en masse, which puts crops at greater risk. Growers and agronomists should continue to check the prediction tool to monitor for new migrations and the extent of that migration. This will help determine when is the best time to monitor crops in order to assess the mean number of beetles per plant for comparison against threshold levels.
Two-thirds of the 83 UK weather stations monitored by the Bayer Pollen Beetle Predictor have had weather conducive to suggest pollen beetle migration has started, albeit at very low levels.