As for wasps. Maybe the 180mm macro would be a better choice for them but it’s not cheap (which is why I rented it) and the cropped bodies (APS-C sensors) (60D, 90D etc) may be the way to go. The extra “magnification” on the APS-C sized sensors is not a huge amount but it’s noticeable.
Mirrorless vs. DSLR: On a mirrorless camera you can get insane frame rates… hold down the shutter and it’s like a machine gun and you’ll capture up to 20 shots per second with the electronic shutter, compared to about 10 shots per second with something like a 90D (mechanical shutter only). If that’s an advantage for wasp photography then mirrorless is the way to go. There are some disadvantages to electronic shutter but you can set it to mechanical with a reduced frame rate. That said, I’ve never actually seen the disadvantages of electronic shutter (e.g. rolling shutter) in the field for still shots. There are advantages to electronic shutters as well (frame rate, silence, etc) and you’d need to read some articles to make up your own mind. I’m shooting on a mirrorless camera now and would never go back to a DSLR just because of the frame rate and the better focus