I remember many moons ago I used to fly BCal LGW-Bermuda-Tampa, and the cabin was always sprayed inbound to Bermuda. Pretty gross for a few moments, and some people find those chemicals affect them.

But on an AA flight MIA-Buenos Aires about five years ago, no spraying after departure from MIA and the cabin was riddled with flies and mosquitoes which made for a horrid flight.

Would much rather the cabin was sprayed where appropriate.