The gentle hum of cicadas is a usual background to a Vineyard summer night. With the hum beginning to get increasingly loud on the mainland, the Times wanted to find out if we could expect these creepy visitors this summer. Lo and behold, the Vineyard is safe.
The periodical cicadas, whose lifecycle is either 13 or 17 years long, are emerging across the Northeast, including the Cape. Matthew Pelikan, who writes the Wild Side column for The Times, explained that the millions of periodical cicadas that are emerging now, and will peak in the beginning of June, won’t have a presence on-Island.
“The Island is geologically new, only about 5,000 years old,” he said, “The cicadas didn’t make it here before the Island became an island.”
The annual cicadas will emerge, but their peak is not until the middle of July. Annual cicadas tend to be larger, growing up to an inch long. They also have dark green to black bodies, and green-veined wings. Periodical cicadas are smaller, with red eyes, black bodies, and red- or orange-veined wings.
Both types of cicadas lay their eggs in the branches of trees or shrubs. The eggs use minerals from the trees in order to grow. Once they develop into juvenile cicadas, or nymphs, they remain in their underground tunnels, sucking root fluid for nutrients.
Pelikan said that the main difference between the periodical and the annual cicadas is the length of their lifecycle. The annual cicadas have a yearlong life cycle, while the periodical cicadas have either a 13- or 17-year cycle. Both types of cicadas track the seasons by a method still unknown to scientists. In the spring of either their first, 13th or 17th year underground, the cicadas emerge.
The lifecycle of periodical cicadas is so synchronized that they are absent for either 12 or 16 years, until they all emerge all at once, producing huge numbers of these insects.
He also shared that the loud hum of the periodical cicadas is actually an evolutionary mechanism to defend against predators.
“The loudness is a strategy to overwhelm any predators. If they all sound at once, birds can’t locate them.” he said.
Despite their noise and prehistoric-looking bodies, these insects are harmless.
