The following is one of our most popular What’s In Your Watershed articles in the Ebb and Flow archive. It was written by Luis Martinez.
It was a hot humid afternoon, just another workday in the Richmond Greenway Bioswale for The Watershed Project’s Green Collar Corps.
I was tending the trees when something caught my eye in one of the leafs in a maple tree. At first glance this leaf looked unusually slender and kind of beat up-as if it had been chewed on by a pest. But as I got closer, I noticed this “leaf” was not a part of the tree but a Praying Mantis.
Stagmomantis californica, common name California Mantis, is a species of praying mantis in the genus Stagmomantis, native to the Western United States. There are four major species of mantis that reign over California: European, California, Chinese, and the Mediterranean Mantis. The Chinese mantis historically played a major part in agricultural pest control. During the 1800s the Chinese Mantis was imported to the U.S. as a means of getting rid of pests in farmland in California. These unusual insects were also kept as pets. The Praying Mantis is known to be one of the most ravenous insects in the invertebrate world. Their diet consists of other, pretty insects as well as small birds and reptiles, amphibians, and even other mantids. In adulthood a Praying Mantis can consume twice its size, growing to four inches long-making this predator one of the most dominant invertebrates in the insect world.
The carnivorous nature of this species is what sparked interest in many agricultural farmers as well as gardeners. Their diet of locusts, crickets, fruit flies, flies, cockroaches, caterpillars, moths, and butterflies, plus meal and morio worms helped farmers control crop-eating pests naturally. These guys pretty much eat anything smaller than themselves-aphids, fruit flies, and ants–and they are not very selective when choosing their next meal. At birth they are only as big as an ant . The egg sac carries about 100 – 200 nymphets (tiny mantises); and they have no larval stage. As they grow, so does their appetite. You can see why a mantis in your garden would be an ideal method of pest control. But where there is a positive side there is usually a negative side: their small prey can include beneficial insects-butterflies and bees, for example, which are important pollinators. Mantises have even been known to catch hummingbirds. You may say “but bees, hummingbirds, and butterflies can fly away!” This is true, but mantises can fly too, and their sharp claws and slender build give them agile speed. These predators reign supreme over the insect kingdom. Large birds, however, eat mantises, so if you have a healthy ecosystem in your yard, things are unlikely to get out of balance.
Welcoming these insects into your garden means an end to the need to use harmful pesticides that not only get rid of pests but also other beneficial bugs. Those same pesticides make their way into our creeks and Bay, so mantises indirectly help improve water quality!
When mantises are allowed to behave like mantises, everyone wins.