Dog-day cicadas, also known as annual cicadas or heat bugs, are a type of cicada that emerges in late summer. These insects are known for their loud buzzing sound and their distinctive black and green bodies. While "dog-day cicadas" is the most common term used to refer to these insects, there are a number of other synonyms that can be used. Some of these include harvest flies, swamp cicadas, and green cicadas. Other regional terms that may be used include jar flies, locusts, and tree crickets. No matter what you call them, these fascinating insects are an important part of the late summer ecosystem.