The first frost had finally arrived and we were dragging a large potted tree to move it to ‘bed’ when we caught the movement of something falling. I bent down and saw the limp form of a large praying mantis. With mixed emotions (I was sad to find her dead, but thrilled at the opportunity to hold her) I gently picked her up. As I examined her, I saw a leg move. “Agh!” I screamed, “She’s alive!” I quickly started exhaling on her body to warm her and rushed her inside.
She has been quietly living on a potted tree in my dining room ever since. She rarely leaves her territory (although she disappeared for two days and reappeared on a table on Christmas morning). She has laid four egg cases. She eats a cricket a day and eagerly drinks water out of a spoon or a dropper. When I offer her water, she grabs the vessel and holds on to it until she’s finished. She hugs the dropper like a baby bottle. She is so tame, she actually seems to enjoy sitting on my hand, as is evidenced by her reluctance to part from it. I liken her to an alligator because, like alligators, she moves slowly, almost in slow motion, until her prey is close, then she strikes with lightning speed and deadly accuracy. After she finishes a meal, she very methodically cleans herself like a cat, wiping her face with her foreleg and running it through her mouth to ‘lick’ it. I’m utterly fascinated.
Like other insects, mantises have six legs and two sets of wings, though most adult females cannot fly. They are generalized carnivorous predators, which means they eat all insects and are even occasionally cannibalistic. They are ambush predators, so they usually wait for their prey to wander by, catching it with their dexterous spiked forelegs and devouring it alive. Some species employ extremely elaborate camouflage and have evolved to mimic the appearance of their surroundings using color and shape, but the mantids with which we are most familiar rely mostly on their green and tan color for their camouflage. Mantises undergo incomplete metamorphosis, born looking like mini adults and shedding their exoskeleton as they grow. Once they reach the adult stage, they will mate. If the male is lucky and his mate isn’t hungry, she may not eat him and he will escape to mate with other females. Once a female has mated, the sperm that she stores in her abdomen can fertilize multiple egg cases, which are known as ootheca. Each ootheca can contain between 30 and 100 eggs, and over the course of her 8-14 month lifespan a female can produce between 3 and 7 egg cases if she is healthy and well fed. My mantis has laid five egg cases since I found her, each one taking an hour or two to produce. The adults do not survive our harsh winter, but the foam around the eggs protects them till spring.
While there are approximately 2300 species of mantis occurring on every continent but Antarctica, the European and Chinese mantises, both introduced to the US, have become naturalized and are commonly seen in Montana. My mantis is a Chinese Mantis, Latin name Tenodera sinensis, and I am sure she is one of the hatchlings from the egg cases we bought at Heightened Harvest late last spring to help keep some of the less desirable insects under control as part of our Integrated Pest Management system. I think they helped make a difference.
The praying mantis is one of a small group of insects, which, like humans, have stereovision, enabling them to look with both eyes at the same spot, thus allowing excellent depth perception. A team of scientists recently discovered that they are the only insect we know of that can see in 3D- also like humans- by fitting them with tiny 3D glasses and showing them movies. Another unique trait mantises share with humans is their ability to turn their head, some up to 180 degrees. This is all evidence that they rely primarily on their sophisticated eyesight to find their prey.
Although they do have an ear (only one in the center of their thorax), their hearing is limited to a range of 30 to 150 kHz. Hu-man hearing only goes up to 20 kHz, so my pet mantis probably can’t hear me when I talk to her. It is thought that they use their hearing to detect and evade predators like bats.
Not only helpful in the garden, praying mantises are one of the most popular insects kept as pets, and it’s no wonder, since, as I have discovered, they are low maintenance and easy-going although, when we took a vacation this winter, we did have to enlist a kind and open-minded neighbor to come feed her. I keep a small container of crickets (which are considerably more difficult to keep alive than the mantis) and feed her one every day or so using a pair of tweezers. She doesn’t make any mess. I mist her with water when I think of it, but that’s as much for the plant where she resides as it is for her. She has provided many happy moments of quiet meditative observation, and a privileged glimpse into another world. There was some momentary excitement this winter when, heavy with eggs, she apparently fell and ruptured her abdomen. She was leaking egg foam and fluid and I thought she was a goner. In a moment of inspiration (and desperation) I applied some superglue gel to her wound with a toothpick, and in a small miracle she stopped leaking and has been fine ever since!
She is cleaning her foot. The blob on her abdomen is where I repaired the leak…
I know she won’t live forever, but I secretly hope she makes it to spring so I can set her free again. Either way, I will miss her when she’s gone.
Submitted by Ann McKean
National Audubon Field Guide to North American Insects and Spiders
Why do Mantids Only Have One Ear?