Yes,there are. I read once that there is an approximate seven-year cycle to this. The last time, 2002, there was a huge influx of hummingbird hawkmoths. This year, as you may have seen on the news, there has been a massive flood of painted Lady butterflies. Millions arrived earlier in the year, have breed and laid and the second brood is now on the wing. Clayton mills, for example, has a lot! RR