David Owens, Extension Entomologist, owensd@udel.edu
Small Grain
Continue scouting for cereal leaf beetle eggs or larvae. Thresholds are 25 per 100 tillers. Although eggs tend to be laid on the upper leaves, some will be laid lower and larvae can also disperse.
So far, armyworm activity has been light, but they are present in some fields along with grass sawfly. Grass sawfly look like green caterpillars but have abdominal prolegs on every segment while armyworm are missing a couple of pairs. Sawflies can be more damaging; thresholds are 0.4 per row-ft (note, this is more than half that of armyworm).
Early Season Moth Activity
Moth activity continues to be fairly light, probably in part due to a couple of wet, cool nights. Trap counts for the week are as follows, with thanks to Joanne Whalen, Emily Zobel, and Maegan Perdue.
| Location | TAW/night | BCW/night |
| Willards, MD | 2 | 8 |
| Salisbury, MD | 0.3 | 0.7 |
| Laurel | 0.7 | 0.4 |
| Seaford | 6.7 | 9.6 |
| Harrington | 6 | 3.1 |
| Pearson’s Corner | 6.3 | 0.4 |
| Sudlersville, MD | 0.1 | 1.1 |
| Smyrna | 3.3 | — |
Soybean
Watch for early season stand reducers closely. Seedcorn maggot seriously damaged some early April planted beans at the research station last year. Slugs are active, and the cool, cloudy weather has kept them active. Warm soils are important for soybean to emerge quickly and outrun slugs. Last year in the damaged plots, stands were reduced by two thirds and yield was reduced between 15 and 50%, depending on the variety and maturity group. This highlights the ability of soybean to compensate for lighter stands if given good growing conditions.