Soybean plants have reached the R1 stage when first flowers open.
OMAFRA specialist Tracey Baute says from now until the start of the R6 stage, soybean aphid thresholds kick in.
For the most part, Baute says aphid populations have remained low.
There is one exception - a Perth County field that's being sprayed in the next few days.
Baute says moderate temperatures can be ideal for aphid development.
And she cautions that even fields treated with neonic seed treatments will need to be scouted.
She points out the insecticide will no longer be in the plants at levels that can control the aphids.
Baute says the free Aphid Advisor app can help growers decide whether there are enough natural enemies to keep up with the aphids or if a spray is necessary.
If a spray is necessary, Baute recommends growers contact beekeepers with hives within 5 kilometers of the field so they can take further measures to reduce the risk of exposure.
