New insect species are always coming in through travel of human belongings, plant material, natural ability to migrate to new geographical location.
Climate change is allowing other non native creatures(which may include insects, plants and animals, viruses, bacteria, fungii) to be introduced into a climactic region that they would not normally be naturally occurring and now thrive.
European Fire Ant Myrmica rubra is one of them. Here are some links on this invaisive ant species: