Peanuts are slowly moving along, weed management and fungicide applications continuing. While hot, the forecast is looking encouraging for possible rain. Familiar insects are starting to show up in some areas. Corn earworm/tobacco budworm, granulate cutworm, and potato leafhopper being a few.

White-margined burrower bug

White-margined burrower bug does not cause damage to peanut, is not the same as peanut burrower bug, and does not require treatment. As its name goes, adults have a white line/margin around the outside of their body. Immature nymphs of the white margined burrower bug are red and black. Peanut burrower bug, the pest, has nymphs that are dark born and tan, with adults being more brown (not black) and without a white margin.

Leafhopper

Leafhopper injury shows up as yellow leaflet tips that can enlarge to look like a "V". Leafhopper usually start at the edge of a field and work their way from there, though it is not always a fast process and I am not quick to recommend treating a field for them, in part due to available insecticides being broad spectrum and contributing risk to killing beneficials and flaring other pests. Leaf symptoms can persist after the insects are no longer present. Walking through or brushing over an affected area and looking for small flying leaf hoppers (smaller than a pencil tip) is helpful to see if they are still present. Often they will land on leaf undersides. I would not be itchy to recommend an insecticide application if less than 30% of leaflets are showing symptoms and the insect is present.

Worms

Our recommendation for treating for foliage feeding caterpillars has been 4 or more worms per foot of row on nonlapped, stressed canopies, or 8 worms per foot on lapped and healthy canopies. Larger Virginia type canopies can probably sustain a little more, though generally too we would like to keep canopy defoliation not greater than around 30%. More specific worm chemistries may be more expensive up front, but they are easier on beneficials and carry less risk of nontarget flares compared to broad spectrum chemistries like pyrethroids.

Leaf scorch/Pepper spot

Leaf scorch is also becoming more visible. Leaf scorch and pepper spot are caused by the same fungus, and both do not pose an economic concern nor require special fungicide applications beyond those typically applied for leaf spot/white mold. Hot, dry, stressed conditions encourage leaf scorch. This disease is more of a secondary colonizer, and early or intermediate symptoms can look similar to thimet injury, though usually thimet starts with more symmetrical symptoms.

Peanut images 6-27-24

Dan Anco

Extension Peanut Specialist and Associate Professor

Department of Plant and Environmental Sciences

Clemson University – Edisto Research and Education Center

64 Research Road

Blackville, SC 29817

630-207-4926 cell

danco@clemson.edu