Tiny street gardens in Amsterdam can support insects. The two factors that offer the biggest boost are having lots of plants and having lots. of different types. But it makes no difference whether the plants are native or not. Research on larger garden plots at Wisley in the UK has produced broadly similar results.
The saddest fact I read was the reason we don't see bugs smashing into windshields at the extent we used to is because the populations have collapsed. I hope we can get them back to that size one day.