A: A population of periodical cicadas, brood XIX, should be emerging in the St. Louis area this spring. These adult cicadas emerge from the soil, climb up vertical structures like tree trunks, mate, and lay eggs in twigs ¼ to ½ inch in diameter, about the size of a pencil. Note that they do not eat foliage, so they don’t create holes in leaves.

The only plants that may be vulnerable to cicada damage are young, newly planted trees and some shrubs. “Female cicadas make slits in small twigs and branches to lay their eggs,” Yiesla said. “On a very young tree, small twigs and branches may be all it has.”

While the cicada “boom” hasn’t occurred just yet, you might be seeing some here and there. The noisy insects have begun appearing as part of the 17-year emergence, though they’ve yet to start coming out of the ground en masse.