In May, for the first time in 17 years, parts of Chicago were blanketed in swarms of buzzing, mating, crawling, red-eyed cicadas, and even the city's tiniest trees were ready.
Homeowners in Chicago covered small trees in their yards with mesh netting and draped them in white cloth to protect them from damage that cicadas might cause while a swarm of cicadas, known as Generation 13, emerged. Another group, Generation 19, emerged around the same time in southern Illinois and many other parts of the U.S.
The veiled trees create a mysterious and striking effect throughout the city and its suburbs, with the purple and green leaves of Japanese maples and elms just barely visible behind the translucent tulle.
Botanists say such coverings are a smart idea because female cicadas lay eggs and then remain pregnant for 13 to 17 years, which can cause short-term damage to some trees and shrubs.
Cicadas don't bite or sting people, but they can harm young trees with thin branches, said Tom Tidens, plant health manager at the Chicago Botanic Garden. Female cicadas make long slits in twigs and lay 20 eggs per slit, for a total of up to 600 eggs.
Tiddens said trees under about 6 feet tall with pencil-sized branches would benefit from wrapping until the periodical cicadas are gone in a few weeks.
The netting may limit new growth, but once the netting is removed the small trees should bounce back within a month or two, he said.
Homeowners with unprotected trees need not worry: “Most trees and shrubs recover just fine from cicada damage,” he says.