Praying mantids prey on smorgasbord of garden insects
Still as a statue, the mighty ninja awaits its opportunity to pounce.
A slow, 180-degree swivel of its triangular head allows her to follow her prey through the jungle of leaves. She keeps her legs folded under her chin, frozen until the right moment to unleash her deadly fury.
Suddenly, HI-YA! The ninja strikes suddenly and with such grace that the surrounding foliage is barely twitching from her death blows to her latest victim.
Her massive forearms act like vice grips on her prey, holding it tightly as it twitches slightly. She watches it struggle with a nearly bored look of, “Oh please, just give up,” in her glassy, bulbous eyeballs. Resistance is futile.
Sure enough, it’s over soon and she enjoys her lunch in the shade, eating the grasshopper like a hotdog at first and then holding it sideways like corn on the cob.
Praying mantids are some of the most distinctive garden insects. It’s easy to pick them out because they don’t really look like anything else, and the varieties that live in Colorado can grow to be quite large as adults.
While they do “prey” on other insects, their name “praying” actually comes from the position their front legs are usually holding: a slightly upheld, angled position that puts their front legs together as if deep in solemn reflection.
The scientific name of the green, European mantid, the one I found most often in my yard this year, is Mantis religiosa.
They also are one of the most entertaining insects to observe, in my opinion. The theatrics of the mantis quietly stalking and attacking its victims are only matched by spiders; however, the mantis doesn’t have the advantage of webs so they must be extra stealthy.
Most of the time, it seems they eat insects their own size or smaller, but sometimes they are more ambitious. I’ve seen one make an attempt at catching a small hummingbird, unsuccessfully.
Some experts consider them less beneficial than other “good bugs” such as lacewings or ladybugs, because mantids have a tendency to eat their own kind, especially when they’re young. This cannibalistic behavior reduces their overall effectiveness.
You may have noticed there are brown mantids and green ones, and some grow to be as big as 5 inches long but others are smaller. That’s because we have at least six different types of mantids in Colorado, according to Colorado State University Extension.
The big, brown ones are the Chinese mantids, and they are usually the ones you’ll find that gardeners purchased to have more good bugs to eat the bad bugs in their yards. According to CSU Extension, these non-native mantids rarely survive Colorado winters, so they’re usually introduced each year by gardeners themselves.
This is the time of year when I start to see the larger, female praying mantids with swollen bellies, indicating they’re full of eggs ready to be fertilized. They’re less graceful at this time and are unable to use their wings as well, since they get heavier.
I should mention that the romantic endeavors of praying mantids have been somewhat sensationalized in pop culture over the years, as have the rumors of the female black widow spider always killing her mate, which is not the rule but rather the exception.
“This does occasionally happen and the male may even continue to mate more vigorously after decapitation,” CSU Extension’s fact sheet on mantids states. “However, this cannibalistic behavior occurs infrequently and usually only if the female is starved.”
Luckily, my yard is a smorgasbord of insects for female mantids and they really have no reason to engage in this sort of kinky behavior. I suppose the risk a male mantis takes in this courtship ritual is underestimating his potential mate’s level of hungriness prior to making advances.
After mating, the females lay hundreds of eggs in a frothy liquid that hardens to protect them through the winter. In the springtime, tiny mantids emerge from the egg cases, which look like a cross between pork rinds and packing peanuts. The nymphs that hatch are little versions of adults who eat tiny food to start, like gnats.
As they grow, they molt, and eventually grow wings as adults, and the circle of mantis life begins again.
If you find these precious little egg cases on your fence, the side of your house or even on tree limbs, let them stay and have a chance at populating your yard next year for episode 2 of “The Garden Ninja Returns.”
I hear the sequel is even better.