How to scout for green peach aphid?
To determine aphid density in a potato field, select 25 lower leaves (be sure to sample full compound leaves – not single leaflets) in each of four areas in the field and count the number of aphids found on the underside of the leaf. Sampling lower leaves is important because green peach aphids prefer to feed on older senescing leaves because they provide the highest food quality in terms of the balance of nitrogen and sugars. Green peach aphids will not be found in the upper canopy during the early stages of population growth. However, avoid leaves that are completely yellowed or in contact with the soil. Historically, green peach aphids can be found in potato fields by mid-July in the Red River Valley. In the last issue of the Aphid Alert we reported finding winged (“alatae”) green peach aphids in some traps and wingless (“apterae”) in some fields. Seed growers should now begin scouting fields weekly for green peach aphids. Remember, all aphids are female, they give birth to live you
