Agronomic Crop Insect Scouting

David Owens, Extension Entomologist, owensd@udel.edu

Alfalfa

If you have not yet begun scouting for alfalfa weevil damage, do so NOW. Alfalfa weevil began hatching a couple of weeks ago from eggs laid in the fall, and I have visited several fields that are well above threshold. The timing of this hatch is a couple of weeks earlier than 2021. Adult weevils are still active, continuing to lay eggs, thus we will have an extended period of weevil larval activity. There is a dynamic threshold based on plant height, control costs, and alfalfa value in our recommendation guide: https://www.udel.edu/content/dam/udelImages/canr/pdfs/extension/sustainable-agriculture/pest-management/Insect_Control_in_Alfalfa_-2020_-_David_Owens.pdf. To sample alfalfa, select thirty stems per field and beat them into a bucket. You may wish to examine the stems after beating because early instar larvae sometimes do not easily dislodge from their hiding places in the folded terminal leaflets. Please also note that thresholds are for pure stands only. There are no thresholds once the alfalfa component of a mixed stand drops below 50%.

Alerts and Apps

I recorded a brief Pest Patrol text alert when we saw the first larval activity. Pest Patrol is a free service sponsored by Syngenta. Users sign up to receive alerts for various crops/regions and when a regional specialist records a message, the system sends a text notification on your phone that links to the 2-5 minute recording. You can find more information here: https://www.syngenta-us.com/pest-patrol.

The MyIPM app for row crops is now live! Check it out!

Scan the QR codes to access the app

Early Season Moth Trapping

We have begun monitoring true armyworm and black cutworm. Moth flight from both species before last weekend’s cold snap was starting to increase to levels that are a couple of weeks earlier than 2021. However, with cold weather this week, flight has decreased. Many thanks to Morgan Malone and Joanne Whalen for checking traps.