Same deal as ladybirds and butterfies (certainly the variety).
Some people sight pollutuon and environmental changes or simply less trees in the metro areas...they possibly have a point, but would be good to hear from people in the sticks - hope these insects are still in abundance in more insect-friendly locations. Some insects thrive in the city - I'd happily swap our some of our cockroaches, ants and redbacks with a few christmas beetles, ladybirds and butterfiles, although maybe not inside the house.
