HIGH NUMBERS of aphids have been recorded in monitoring traps around the country, according to latest reports.

Recent mild weather appears to have increased aphid activity and sugar beet growers who have not used treated seed must be especially on guard, warned Mike May from Brooms Barn research centre.

“We were forecasting high numbers and we are certainly seeing them.

“Aphids have appeared very early and in very large numbers. The cold spell earlier in March doesn’t appear to have affected them.”

While aphids have been caught in traps across the country, the highest numbers have been found in Apley, Shropshire and Shropham, Norfolk, he said.

Sugar beet growers with non-Gaucho (imidacloprid)/Poncho-Beta (beta-cyfluthrin + clothianidin) treated crops should pay very close attention and be prepared to spray, he advised.

“The other concern is whether there are any [MACE] resistant aphids around. Some look as if they could be, but we have not had chance to test them yet.”

Aphids will be drawn out onto leaves during warm sunny days and growers should check crops around every three days, added the Scottish Agricultural College’s Simon Oxley.

Aphicide treatments only need to be applied if 50% of plants assessed have colonies present, he said.

Even then growers should wait a few days to see if numbers are reduced by natural predators.

If aphid numbers remain above this threshold level, then growers should consider an aphicide, he said.

He recommends pirimicarb (e.g. Aphox, Phantom and others), as it is less harmful to beneficial insects. Growers can see pictures of these insects at www1.sac.ac.uk/crops.