I'm sorry to hear about this issue. Thanks for sending videos. I can't determine acute pesticide honey bee kills just by watching videos (there are many other things that can cause a honey bees to die, and there are a few other things that can make them twitch), but I think this case warrants an investigation. Please see What to do if you suspect your honey bee colonies are harmed by pesticides - Beekeeping & Pollinators (https://www.canr.msu.edu/resources/what-to-do-if-you-suspect-your-honey-bee-colonies-are-harmed-by-pesticides). 

Your next step can be to Contact Michigan Department of Agriculture and Rural Development (MDARD). Bee kills can be reported through MDARD's pesticide complaint online form (which I believe is MDARD's preferred way of receiving these complaints). MDARD can also be reached by phone at <personal data hidden> or by email at <personal data hidden>. Pesticide complaints are handled by the Pesticide and Plant Pest Management Division. 

Some pesticides break down quickly, so it's important to contact MDARD right away. Even if you collected samples of dead/dying bees, MDARD will likely want to do its own investigation. States report pesticide bee kills to the EPA, which can provide data for pesticide regulations and renewals.

MSU has provided training to MDARD pesticide inspectors for several years in honey bees. Most pesticide inspectors deal with other kinds of pesticide investigations and rarely get called to inspect honey bee colonies. Even though they aren't experts in apiculture, the inspectors who I know care very much about supporting beekeepers. If an inspector comes out, it would be helpful for you to be prepared with hive tools and a smoker. You could expect to open the hive and manipulate the frames for the inspector to see. It would be helpful if you managed the colonies and used smoke to prevent defensive behavior. MSU (especially me and Meghan Milbrath) are happy to answer questions that you or the inspector has.

Some other questions I have:

- What kind of field was being sprayed? Do you know what is planted there or what was planted in the field in the past?

- Are there flowers in bloom in the field that was sprayed? If so, what kinds of flowers?

Please feel free to follow up and keep us updated.