October 30, 2020
Pests to keep an eye on this week
Richard Derbyshire, Bartonfields iFarm Coordinator, 30th October 2020
Keep a look out for these pests in your emerging cereal crops:
Aphids are still active and landing in cereals. BYDV carried by these can severely knock yields if left unchecked. BYDV carrying aphids can cause severe damage if left unchecked, and a pyrethroid spray should be applied now, perhaps with post em herbicide and manganese. The situation will need to be monitored for re-infection but Agrii’s Contour digital programme can help with prediction of aphid movement by collation of average daily day temperatures and historic weather data, giving us an idea when thresholds might be reached.
The last photo below shows slug eggs found on clay soils in Leicestershire. Lack of rolling, weather and ground conditions are favouring slug activity at the moment. Watch out for grain hollowing and leaf grazing. A plastic bag pinned down can be used to give an idea of slug numbers if checked regularly. Any cereal after OSR will be under the highest pressure but watch any seedbeds that allow good access to drilled seed, after grass if not rolled for example.
Frit fly larvae
Dead hearts from Frit fly larvae are being found quite easily at the moment. Normally a pest seen after grass, we are finding them where there hasn’t been grass in the rotation. The loss of Dursban etc has has taken away any chemical control so we’ll need to rely on cultural methods. Re-drilling could be needed in the most severe cases but early spring N and rolling the crop next spring will help to stimulate tiller numbers where moderate.
Keep your eyes peeled!
Top (L-R): Dead hearts caused by frit fly, Frit fly damage
Middle (L-R): Frit fly larvae, Aphids
Bottom: Slug eggs in Leicestershire