Black Bean Aphid (Aphis fabae) Forecast 2026

The timing of the migration of Aphis fabaeat any location can be predicted using the mean air temperature and the site’s latitude and longitude. A range of equations were produced in AHDB Project FV 407a describing the relationships between the dates of first, 10% and 50% capture of aphids in suction traps and the mean air temperature over different periods and site latitude and longitude.

Forecast based on air temperatures (January-April)

	First	10% aphids	50% aphids
Cornwall	12-May	9-Jun	7-Jul
Kent	2-May	13-Jun	4-Jul
Suffolk	30-Apr	14-Jun	4-Jul
Wellesbourne	19-May	23-Jun	15-Jul
Norfolk	14-May	26-Jun	13-Jul
South Lincs	22-May	30-Jun	18-Jul
Nottingham	21-May	27-Jun	18-Jul
Lancashire	1-Jun	2-Jul	24-Jul
York	9-Jun	14-Jul	29-Jul
Scotland	6-Jun	19-Jul	2-Aug