Should You Be Concerned About the Grizzled Mantis?

Extension agents occasionally receive calls about “alien” bug sightings, sparking concern among residents. One such insect, Gonatista grisea, commonly known as the Grizzled Mantis, Florida bark Mantis or Lichen Mimic mantis, often raises alarm. But there’s no need to panic—this mantis is a fascinating and harmless part of our ecosystem.

The Grizzled Mantis is native to the United States, ranging from southern Florida to Georgia and South Carolina, and is also found in Puerto Rico, Jamaica, and Cuba. Adults are relatively small, with males measuring 36–38 mm and females slightly larger at 37–40 mm. Their grayish-green coloration and mottled dark markings provide excellent camouflage, allowing them to blend seamlessly into their surroundings, such as lichen-covered bark. They are characterized by triangular heads and large eyes, perfect for their ambush hunting style.

Quick and agile, Grizzled Mantids scuttle rapidly away from perceived threats. They exclusively prey on arthropods, adopting a head-down ambush position while resting on tree bark. Their preferred plants include sea grape, gumbo limbo, water oak, and magnolia, though they are not limited to these species.

Interestingly, mantids are gaining popularity as low-maintenance pets. Some enthusiasts collect egg cases or purchase late-stage nymphs. However, keep in mind that newly hatched mantids require ample food or separation, as they can become cannibalistic if resources are scarce.

Whether in the wild or as pets, the Grizzled Mantis is a unique and beneficial insect, playing a role in controlling arthropod populations. So, the next time you spot one, there’s no need for fear—just appreciation for this remarkable creature!

For more information, contact your local Extension Office or click on the link Grizzled mantid – Gonatista grisea.