Annual cicadas are different from periodical cicadas. There are 3 species and they reappear every 13 or 17 years. They provide food for birds and they need trees to survive. Wasps are our allies. Paper wasps rescue our trees, crops, and other plant life by eating insects such as caterpillars and cutworms.
Fireflies are in a pattern of decline.
They are really beetles, not flies, and their larvae are glowworms. Firefly flashing has to do with sex. Males use flashes to signal females and the interval between flashes identifies the species. There are about 2000 kinds of fireflies in the world. Another summer night time visitor is the bat.