Soybean Aphid and Rust Update
By: Mike Stanyard

Soybean aphids (SBA) have made their annual flight from their winter host, buckthorn, to colonize young soybean plants. Reports from the Midwest last fall predicted this would be a banner year for SBA. This was based on increased numbers of winged aphids migrating out of soybeans to lay eggs on buckthorn. I did not notice any high populations in the field last fall.

On May 11th, researchers from Penn State came to NY to look for emerging SBA on buckthorn. We scoured the brush at three farms in Wayne County and found aphids at all locations in hedgerows and on the edges of woodlots. At that point, we could not make any determinations on potential populations, only that they overwintered successfully.

Many soybean producers planted earlier than normal this year but we did not get the first report of SBA until June 9th. This is right on time compared to previous years. We are now getting reports of aphids across the region. Hopefully, this native population will be controlled by natural enemies and rain storms. However, on June 16th, we found a field in Seneca County with an average of 30 aphids per plant with no sign of ladybugs. This field will have to be watched closely as populations can multiply exponentially is left unchecked. Fields treated with Cruiser seed treatments have all looked clean so far. Remember, SBA thresholds are still 250 per plant. However, if other stresses like drought or high populations on very small plants, we might need to lower that threshold.
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