Garden Detective

Mystery monster actually a harmless native

I just saw this huge bug on my rosemary for the first time (in late July). It was over an inch and a half long. It is scary looking and I hope it’s not some kind of new invasive insect. I’ve never see it before. Can you tell me what it is and if I should trap or kill it?

Brandon Chee, Sacramento

Relax. It’s a harmless native known mostly for its noise — and more associated with other regions of the country.

“This insect is a cicada that is native to the Sacramento area,” said entomologist Baldo Villegas of Orangevale. “They are best known for their unique sounds in the summer months. They normally are found in the Sacramento area in the summer months of June and July.”

They look scary, but don’t worry about this visitor.

“They are harmless and do not sting or bite despite their size and their look,” Villegas said. “They have a long proboscis between their legs and under the head that is used for sucking sap from plants and roots. Females have a powerful sawlike ovipositor (egg laying structure) that is used for laying eggs in branches of trees and shrubs.

“They generally emerge from the ground where they spent the previous year as a nymph in the soil, feeding on plant roots,” he added. “As adults, they only live a few weeks — just enough to mate and lay eggs.”

Occasionally, the cicada moms may do some landscape damage.

“The females will lay their eggs in tree and shrub branches and, in the process of positioning their eggs, they may cause damage to the branches of such trees, Villegas said.

Even if you wanted to trap this cicada, he’s probably long gone.

“The adult in the picture probably emerged that very morning and probably cannot fly due to the fact that it takes several hours for the outer skeleton of the insect to harden,” Villegas said. “However, as soon as the skeleton hardens, the cicada will fly away and I doubt if you will ever see it again.”