An Update on Arrival of Black Cutworm in Pennsylvania

 

As reported previously, our Black Cutworm Monitoring Network had detected four significant flights of black cutworm moths in our pheromone traps. Since our report last week, we have added an additional significant flight in Montgomery County, near Souderton. In these areas, one should expect an elevated risk of cutting damage by caterpillars later in the spring. For better or worse, the colder temperatures this week has slowed down caterpillar development.

 

 

Cutting damage from black cutworm caterpillars tends to occur about 300 degree days after these flights, so the time to scout at any of these locations has yet to arrive (note the degree-day accumulations thus far in Table 1), but could arrive soon in Lebanon County if warm weather returns. For areas not listed, the degree-day accumulations for the closest location can be used to approximate the time to scout, but I usually recommend that fields get scouted every 7-10 days and this “regular” scouting should detect black cutworm damage. When scouting your fields, note that black cutworm caterpillars can damage corn from first emergence up to V4 or V5. For young plant, cutworm damage can look like a series of symmetrical holes through the leaves (Figure 1). Remember that if cutting damage is found, rescue treatments are usually the most efficient and economical tactic for managing black cutworm. For more information, see our black cutworm article .

 

Video: Sclerotinia and Lygus in Seed Canola: Field Update with George Lubberts, CCA | Enchant, Alberta

Join Certified Crop Advisor George Lubberts for this Prairie Certified Crop Advisor (Prairie CCA) field update from Enchant, Alberta. In this 12th video of the series, George takes us into a seed canola field where the male rows have been removed and the female plants are filling pods. This video was taken in the third week of August 2025.

George discusses the early signs of sclerotinia stem rot, explaining how infection begins in the stem, impacts pod development, and leads to premature ripening. He also shares insights on lygus bug management, including timing of spray applications to minimize feeding damage and maintain seed size and quality.

With cool, damp summer conditions, George notes that while disease pressure is present, overall field health remains good. The crop is just beginning to show early seed colour change, signaling progress toward maturity.

Topics Covered:

•Sclerotinia stem rot identification and impact

•Managing lygus bugs in seed canola

•Crop stage and seed colour change observations

•Timing insecticide sprays for optimal protection

•Insights from a CCA field perspective in southern Alberta