Speaking of Nature: Praying mantis
Summer is a strange time of year. Some days seem to linger forever, while others seem to be nothing more than a notion, evaporating away like much of the water evaporates from the landscape under the heat of the summer sun. Summer starts with a profusion of avian activity, but as the days click by, the birds also seem to evaporate. The world is full of life and activity one moment, then apparently devoid of it later. But this is only an illusion.
On Saturday, I went down into the meadow behind my house to see if I could “look behind the curtain” and see if there wasn’t a bit more activity than there appeared to be. As I stood among the shrubs and small trees at the edge of the high grass, I gradually picked up on the locals as they came out of hiding. The little house wren that filled the July air with his incessant singing may be quiet now, but his offspring are causing all manner of hullabaloo down in the meadow. They are just being quiet about it.
I’ve also heard a great deal of barred owl activity over the past week or so. The young owlets have surely fledged by now and need a lot of attention from mother and father as they figure out the ins and outs of owldom. Youngsters stray into other territories, incite all sorts of brouhaha and need a rescue now and then. Parents get agitated, quiet evenings are lost to intense drama and I sit on my porch and smile as I listen in the dark.
On Sunday, I caught sight of a bird that really got my attention. A young blue-gray gnatcatcher was exploring the trees across the road and the moment my eyes locked onto the mockingbird-esque plumage of that little bird, the lateness of the hour really struck home. The fall migration is about to start in earnest and the landscape will soon be abandoned by most of our birds.
But while this is happening, the insects will reach their zenith. So, to finish off my August celebration of the insects, I want to focus on a particular species that is always very interesting to see. It is not a cricket, nor is it a grasshopper, but as these groups of insects provide the music of the late summer, one of their predators lurks in the grass, waiting for them to make mistakes. I am speaking, of course, of the praying mantis.
Finding one of these insects can be rather touch and go. Sometimes there seem to be mantises all over the place, while other times there doesn’t seem to be any to be found anywhere. I don’t know the reason for this, but I do know that you can greatly increase your chances of finding a mantis by looking in the right place. From my experience, that means finding an area with tall grasses that have not been disturbed by mowers for some time. As luck would have it, that’s about a third of my yard.
The other thing you need to know is that a praying mantis can fly. It seems like such a big gangly insect to begin with, but when you add the prospect of powered flight into the equation you end up with an organism that becomes even larger and ganglier in the air. And thank goodness for that, because, nine times out of 10, that is how I find them.
As I walk through the tall grasses of fields, or preferably along the nicely mowed trails that have been maintained in such fields, I find that I kick up many different sorts of insects in front of me. The grasshoppers are the fastest; moving with a suddenness that makes getting a good view quite difficult and following ballistic trajectories that makes tracking them even more of a challenge.
Then there are the various moths and butterflies that get disturbed, but they are fairly easy to recognize. What you need to look for is a surprisingly delicate-looking insect that moves rather slowly on gossamer wings. As I mentioned before, mantises are rather large and their wings are about the same size as those of the larger dragonflies. The difference is that mantises flap their wings like birds, which means that they can’t move too quickly.
As a result, mantises tend to be easy to spot and quite vulnerable to bird predation if they fly during the day. They will fly if they find themselves in immediate danger, but typically they do most of their flying at night, when birds are not such a danger. Males are particularly motivated to fly in their efforts to find females by homing in on their pheromones. Bats still pose a threat, but mantises have evolved with the ability to detect the echolocation calls of bats and take evasive measures.
There are mantises native to the United States, but most of them are found in the southern states. Because of their predatory behavior (one possible explanation for their name), it turns out that mantises are popular as biological control candidates. Various species have been spread around the world in the hopes that they will control pest insects. One of these is the European mantis (Mantis religiosa) and it was this species that I encountered in my lawn last week.
Mantids are accomplished predators armed with rows of spines on their front legs. Toward the distal portion of their front legs, they have particularly large spikes that are used as stabbing and impaling weapons. In a fashion similar to a hunting great blue heron, mantids hold their legs in a cocked-and-ready pose in front of their bodies. When a prey item, like a nice juicy cricket, comes within range, the legs lash out in a killing maneuver.
Mantises are ambush hunters, which means they need to be able to blend in with their surroundings and strike out when a careless victim strays too close. In order to blend in with their surroundings (which tend to be rather grassy as I mentioned earlier), they can be found in colors that range from a minty-green all the way down to a dead-grass brown.
Male mantises tend to be smaller and more slender, which helps them to fly in search of females with greater ease. Females tend to be longer and their abdomens can become quite plump when their bodies are loaded with eggs. These are laid in easily-identifiable cases that can be found on grass stems, but I also find at least one on the side of my house every year and several in the wood pile as I stack wood in October.
Adult mantises have no way of escaping the cold of the winter, so the eggs represent all of the mantises that there will be in the following year. If you should happen to find one somewhere, particularly if you find one on your own firewood this fall, just put it to the side in some quiet corner of your yard and you should have plenty of mantises next year.
While selecting photos from my collection, I noticed that all of them were taken in August and September. So this is the time to go looking for them. Head outside on any sunny weekend and try to find an area with some tall grass. This is the time of year when the mantises are at their largest and their busiest, so keep your eyes peeled and if you are lucky you just might find one.
Bill Danielson has worked as a naturalist for 16 years. In that time, he has been a national park ranger, a wildlife biologist and a field researcher. He currently works as a high school chemistry and biology teacher. To contact Bill, or to learn more about his writing, visit www.speakingofnature.com