A great bug emergence that hasn’t occurred in hundreds of years set to arrive this Spring

BOSTON — Trillions of cicadas are expected to emerge this spring in a rare double-brood event that hasn’t happened in over 200 years and won’t happen again until 2245.

There are two types of cicadas: periodical and annual. Periodical cicadas are among the longest-living insects, emerging in the spring every 13 or 17 years.

Annual cicadas emerge every summer with life cycles ranging from 2 to 5 years.

The two broods emerging this spring are a 13-year brood cicada and a 17-year brood.

They are expected to emerge across more than a dozen states in the Midwest and Southeast, with a possible overlap in Illinois and Iowa.

Cicadas emerge from the ground when temperatures are slightly warmer — typically in late May and will last through June.

Cicadas can be loud, especially when there are so many of them.

Scientists say they are harmless though. In fact, the EPA says they can actually provide some benefits. They aerate the ground, are a valuable food source for animals and birds, and can add nutrients to the soil as they decompose.

A 17-year cycle brood will emerge across parts of southeastern Massachusetts in 2025. But we don’t expect cicada broods this spring to have much impact in New England.

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