As I walked through my test plots and a few commercial peanut fields this week I noticed that we are starting to see some potato leafhoppers and very early hopper burn. UGA Extension agent Rome Ethredge in Decatur County also mentioned that there was some heavy leafhopper pressure in at least one field in southwest GA this week. We need to be observant as we scout fields in the coming weeks. Low level leafhopper infestations are very easily overlooked, and scouting from the truck will almost guarantee that you will not see them until the hopper burn is bad.
Hopper burn will appear as yellowing of the tips of the leaves. This yellowing can be very dramatic when infestations are heavy. It is worth mentioning that hopper burn will not immediately go away once the insects stop feeding. This means you should confirm that potato leafhoppers are still active in a field with hopper burn before making an insecticide application. Scouts should be aware that leafhopper infestations often begin at the edges of fields and spread from there. Be sure not to overlook edges as you walk your fields.
There are no validated economic thresholds for potato leafhoppers. The presence of adults and nymphs in the field means that reproduction is happening, and populations are likely to grow. We do not want to be too aggressive with this pest, especially in hot dry conditions where insecticide sprays could trigger secondary pest outbreaks. Nevertheless, we do want to prevent severe hopper burn. See our post on 27 May 2015 for pictures of hopper burn on peanut.