Crop-destroying aphid pests will start to fly about two weeks earlier than average this year, a new forecast shows.
The relatively early flights are due to winter temperatures being about 1°C above the 30-year average across most of Britain.
When it comes to the first aphid flights, temperatures in January and February are critical, AHDB Aphid News service says.
The spell of unseasonably warm weather at the end of February, in particular, has really helped push aphid development along this year.
Two forecasts are available. The forecast for cereals covers bird cherry–oat aphid, rose–grain aphid and grain aphid, and the forecast for brassica and potato covers peach–potato aphid, potato aphid and mealy cabbage aphid.
The estimated date ranges for the first aphids to be caught at suction trap sites across Britain are detailed in the forecasts.
However, there is considerable uncertainty associated with the forecast dates at specific sites. The main purpose of the forecasts is to indicate how the current season compares with the long-term average. The information can be used to help focus in-field monitoring efforts.
It is also important to note that some aphids overwinter in crops and are likely to be present before aphid flights commence.