The past three days featured almost unbearable 90 degree plus days, compounding extreme dry or drought conditions for the 2024 crop. It ended with a 1 inch plus rainfall for some in the Northeast on Tuesday night. Prior to the precipitation, both corn and soy were demonstrating heat stress. One of the oddities found while scouting our now mostly R6 (full seed) soy was Thistle Caterpillar. The Lepidoptera adult is also known as the Painted Lady Butterfly. Thistle caterpillars are not known to overwinter in Illinois but migrate north annually from the southern US and Mexico. The caterpillars form webs by tying leaves together with silk creating a protected area for them to feed. Almost always considered a sporadic pest, it rarely causes enough defoliation to warrant treatment.
Today, Dr. Boris Camiletti, Plant pathologist with the University of Illinois shared his observations on the 2024 growing season from a plant disease standpoint to a gathering of Northeastern Illinois farmers. Diseased crop samples brought to the meeting were identified as Tar Spot, Northern Corn Leaf Blight, Gray Leaf Spot, Southern Rust and White Mold. In addition, ear rots Fusarium and Penicillium were found. Dr. Camilletti encouraged growers to continue scouting practices to aid in management decisions, make use of the Illinois Plant Clinic, and be on the watch for Red Crown Rot in soy that it is progressing its way north in the state.