This post is overdue but (hopefully…) signals the end of the alfalfa weevil season for most of NEK. KSU Extension Field Crops Entomologist Jeff Whitworth expressed to me multiple times this season his disdain for this pest. I’m increasingly in agreement as a second year of heavy pressure started early and caused way too much damage. This is an example:
The bad: that’s a lot of damage. The good: the leaves in the upper RH corner surround a pupal case, signifying feeding was likely wrapping up in the southern reaches of the District. This image was from earlier this week along the Nebraska line showing the same in the northern part of the District:
So while the season is winding down, remember: no two fields are the same! This graph shows two fields – neither receiving an insecticide – with increasing weevil levels in one field while numbers declined in the second. More on the multiple reasons why in a future post…
What about insecticide efficacy? I’m hearing mixed reports from growers and retailers alike with this graphic telling a little of the story (no data = sprayed):
The take home: some applications worked really well. Others worked, but maybe not quite as well! The reasons are numerous and I’ll try to share a little of what I’ve gleaned from observations this spring over the next few weeks in preparation for 2025. It underscores Dr. Whitworth’s continued reminder that this isn’t a complex insect – but that doesn’t make it easy to manage!
