Those are two very good questions. I'll answer the second one first.
Actually, I think that 4.7% of all of the records in eBird are actually non-native species. In Canada, that would be things like the European starling, house sparrows and pheasants.
One of the things we've done in just the last year is to classify across the entire world where things are exotic and established, and where they seem like they might be increasing and it's worth paying attention to as an early warning indicator system that non-native species may be expanding. This is something that the USDA has been particularly interested in. Also, then, it's about being able to understand it if there are unusual things, like somebody's parrot escaping. If somebody's parrot escapes in Florida, though, and there are multiple parrots that escape, all of a sudden you might have a situation that you hadn't thought could get out of control, so in the case of birds, yes.
I also know that within iNaturalist, there are a lot of efforts where people are actually photographing trees. In the case of the emerald ash borer, you're able to see the strips. Citizen science broadly is a very good way to deal with invasive species.
Could you remind me of the first part of your question?