I am not from the Gulf Coast area. I think mosquitos are a problem there year round, though maybe less so in winter. My family is from about 150 miles NW of there, in SW Mississippi. I know mosquitos can be a problem there for sitting on a deer stand in warm winters, even in mid-January.
The person who reported it to me has lived there for over 30 years, and never seen anything like it — ever. That resident doesn’t believe it has anything to do with mosquitoes or crops, as they’ve never seen it before.
It’s not a pollen cloud as someone suggested. The witness saw liquid dropping from multiple helicopters. That’s why they took the picture, because it was happening repeatedly. In formation.