David Owens, Extension Entomologist, owensd@udel.edu
Alfalfa
Mid-to Large alfalfa weevil larvae are still present in some fields. Alfalfa is growing well now, so check its height and compare your counts per 30 stems with the threshold table found in the UD Alfalfa Weevil fact sheet.
Small Grains
Insect activity in small grain in general appears to be very low this year. At current growth stages, aphid thresholds would be extremely high. Armyworm activity does not appear to be unusual. A scout did report seeing a cereal leaf beetle; thresholds are 1 (adult, larvae or egg) per 4 tillers. I have not seen a field at this level in Delaware in the last 7 seasons. You can find good guidance on managing late insect pests here: https://www.udel.edu/content/dam/udelImages/canr/pdfs/extension/sustainable-agriculture/pest-management/Insect_Control_in_Small_Grains_2020.pdf.
Slug Scouting Update
Soybeans are going in the ground now. You can check for slugs by kicking over residue, particularly in the morning or by using sone sort of shelter trap. There are no established thresholds for slugs, a general rule of thumb is to pay close attention to stand when there are 1-2 slugs per square foot present, and especially if wet conditions come in. We are now looking at 16 fields on Delmarva (with assistance from Drew Harris and Nick Adams) and continue to struggle to find any slugs.
Early Season Moth Activity
Many thanks to Haley Sater and Joanne Whalen for checking traps for us. Moth activity decreased this week on account of cold night considerably this past week compared to last week’s report on account of cool and wet weather. Trap counts are as follows:
| Location | # nights | True Armyworm | Black Cutworm |
| Salisbury, MD | 7 | 24 | 32 |
| Laurel, DE | 7 | 10 | 30 |
| Seaford, DE | 7 | 72 | 46 |
| Harrington, DE | 7 | 117 | 49 |
| Suddlersville, MD | 7 | 7 | 35 |
| Smyrna, DE | 7 | 135 | 34 |
| Middletown, DE | 7 | 2 | 4 |