10/20/2019
Summer and fall are great times to look for Praying Mantises (also called Praying Mantids). You may have noticed them in your yard as they wait patiently for insects to pass nearby. As a sit-and-wait predator, Praying Mantises quickly grab these prey with their forelegs. Spines on the forelegs pierce the insect and help the mantids firmly grip their prey.
During autumn, females lay eggs on twigs and other structures. Next, they cover the eggs with glandular secretions that seal the eggs in a styrofoam-like egg case (ootheca). Eggs overwinter within the case and several dozen nymphs emerge in spring. Nymphs grow into adults during the summer and then mate and lay eggs in late summer and autumn.
Here in the Southern Piedmont, there are two species you might encounter. See below to learn how to tell these Praying Mantises apart and distinguish their egg sacs. Notice that on the inset Carolina Mantis egg case, the nymphs have already emerged, hence the slit-like openings. The native Carolina Mantis is the South Carolina state insect!
Some gardeners purchase Chinese (Oriental) Mantis egg cases for pest control in their garden. There are two problems with this. First, this mantis is not native, and in my experience, it is much more common than our native Carolina Mantis. Second, the Chinese Mantis is a generalist predator that will eat a lot of non-pest prey such as bees, wasps, and spiders. As a consequence, the Chinese Mantis isn’t an effective biological control option for pests in your garden.
If you want to learn more about native predators that can help you control pests in your garden, I suggest talking to the experts at your local Ag Extension Office. You may want to ask them about using native Green Lacewing larvae. They would likely be a more effective control agent of garden pests than Chinese Mantids. See my posts on Green Lacewings in the comments below. If you wish to control Chinese Praying Mantises in your yard, see the link from the Maryland Invasive Species Council in the comments below for how to destroy the egg case.