This past week on one of our breezy days, the cover blew off the grill. Of course, it was not the wind’s fault, more like mine as my wife said — what did you expect if you did not fasten it down? So, out the back door I went to chase down the grill cover across the neighborhood.
Upon returning to the grill and unfolding the cover, out popped a praying mantis. The mantis fell to the ground and stared back at me with those large eyes on its triangular head. I was waiting for it to do something; instead, it just stared and stared.
Like an idiot, I said, “Hello there. Did you have a nice ride in the grill cover? Are you OK or injured?”
Of course, my wife came to the back door and said, “Who are you talking to?”
So, this begs the question: Are praying mantises intelligent?
Their shape and posture are distinctive, and their large eyes, mobile head and alert, watchful behavior make them seem smart as they look like the creatures or aliens from the outer space movies.
However, they are no smarter than other insects. (Some entomologists believe that cockroaches are the smartest of the insect world, though I digress.)
This is the time of the year when mantises are often seen. Three mantises are found in Ohio including the Carolina mantid (Stagmomantis carolina), a native species; the European mantis (Mantis religiosa), an introduced species, and the Chinese mantid (Tendora aridifolia), also an introduced species. The Carolina mantid is the smallest of the three and the Chinese mantid is the largest.
Mantids have one generation per year in Ohio. They spend the winter as eggs in a foam-like structure called an ootheca. The highest total number of mantids occurred in the spring when nymphs (immatures) hatched from the eggs. As the season progressed, total numbers steadily declined owing to nymphs becoming table fare for other predators, as well as each other. Also, mantid nymphs can change their colors during each molt to match their surroundings. So, not only were they smaller than the current crop of new adults, but they were also well camouflaged and more difficult to detect.
Mantids are ambush predators, and their meat-eating lifestyle is personified by their specialized raptorial forelegs which are designed for grabbing and holding prey. Their common name comes from the position they hold their front legs while at rest; they look like they are praying. Of course, it is their prey who should be praying because few victims elude death once they have felt the hug of a mantid.
This prey includes male mantids — mating is not about hugs and kisses. Females are notorious for sometimes practicing “sexual cannibalism,” meaning a female mantid may consume a male right after mating.
There are several mantid myths including the perception that they are effective biological control agents and the misconception that mantids are protected by state and federal laws. Mantids are not particularly effective in helping us deal with insect pests. There are usually not enough of them in one location (they’re very territorial) to keep insect pest populations in check and they do not discriminate between what we consider to be insect pests, versus beneficial insects.
Mantid egg cases are often marketed as a natural method of pest control and can be purchased for release in the garden. Because of their territorial nature and their nondiscriminatory insect appetite, releasing these into your garden may not necessarily improve pest suppression. However, releasing mantids will not do any harm to the garden and observing mantids can be a great way to introduce young people to entomology.
There are no laws protecting mantids based on their usefulness as predators or because mantid numbers are declining. Other than normal seasonal fluctuations, mantises of all species are plentiful and there are no endangered species — except the one that had the ride of its life in my grill cover.