Growers who have sown cereals early this autumn have been urged to be on the look out for signs of Gout fly and be prepared to treat crops.

The pest has been recorded across East Anglia and as far north as Lincolnshire, with crops emerging in September at greatest risk from attack, according to Syngenta.

Cereals should be inspected for signs of egg laying on young leaves and where treatment is required, timing is key, said the firm’s insecticides manager, Michael Tait.

“Application timing, to coincide with egg hatch, is all important for effective control; for optimum results the window of application is about a week.”

He suggests using Hallmark Zeon (lambda-cyhalothrin) at 50ml/ha, which is the only foliar pyrethroid insecticide with approval for Gout fly control and also has an effect against aphids.

“Mild weather could see the current high level of aphid infestation continue well into the autumn, so growers should be ready to continue treatment options whilst the threat of aphid activity is present.”

Gout fly summary:
• Two generations per year (May/ June and Aug/ Sept)
• Adults are 4-5mm long with yellow and black markings
• Eggs are typically cigar-shaped, 3-4mm long
• Eggs hatch in 7-10 days
• Larvae (yellowish colour) burrow into centre of plant, feed for 4 weeks, then pupate
• Pupation lasts around 5 weeks before new adult emerges
• Affected plants normally stunted in winter and early spring
(Source: Dow AgroSciences)