Current weather conditions in Ukraine and Russia has been dry and unseasonably warm which will favour cold blooded aphids.In warm weather aphids migrate into winter cereal crops and reproduce.
The issue with aphids this time of year is not injury from
direct feeding but as they feed they introduce plant viruses much in the same
way intravenous drug users do when sharing a needle.
They transmit barley yellow dwarf luteovirus (BYDV) and very
low populations, which may go unnoticed, can cause economic damage.
The two aphids in question are Grain Aphid (sitobion avenae)
and Bird Cherry-Oat Aphid (rhopalosiphum padi) both of which I have seen in
Ukraine and Russian.
As yet have never met a local agronomist who knows what they
are or could identify one.
These two aphids and the problem they cause have been
well documented in Western Europe but I haven't seen any research data or
information on control or thresholds in Ukraine or Russia.
I'm not saying it’s not there I just haven’t seen it or have
been shown anything by local agronomists.
In the UK losses up to 2.5mt/ha have been recorded, losses in Ukraine and Russia might be low but they
could be significant.
Control is based around imidacloprid seed treatment and autumn
applications of pyrethroids, neither of which are currently done so if they are
causing a problem they are not being controlled.