On Sunday, a praying mantis showed up in the foliage of one of our garden plants.
It was soon easy to see why, as the clouds of white flowers were drawing a smorgasbord of bugs – bees, wasps, flies, mosquitoes.
Then the delta head of the mantis swiveled toward a point of interest. The mantis closed on a bee.
In a flash of long, saw-toothed legs, the bee became a meal. A few bee carcasses littered the ground inside the plant perimeter.
After eating voraciously for days, the mantis drew a mate. They were together for a day and a night. Then they disappeared.
The pattern is well known to Mike Raupp, a professor of entomology at the University of Maryland.
The mantis begins its life in spring as a nymph, looking like a miniature adult and emerging among multitudes from an egg case deposited on a branch the prior fall by a female.
“They gobble each other up before they disperse,” Raupp said. “The lucky ones that get away from their siblings then will spread out and begin to consume things in the garden.”
They grow and then, by the fall, their one-year life cycle is on the ebb. With sufficient food and opportunity, the females can mate more than once and deposit more than one egg case, or ootheca, according to Raupp.
For the males, such repetition is less likely, since the females engage in “sexual cannibalism,” where they eat their mates. “You do leave progeny behind. So it’s a noble sacrifice in that regard,” Raupp said of the males.
The effect of the mantis presence can depend on one’s point of view. Carpenter bees were the only insects that I saw the mantis eat.
“Some would consider the loss of a carpenter bee as a negative because they are natural pollinators,” Raupp said. “Others who are having their deck and siding riddled with carpenter bees would consider it a benefit.”
The mantis on my plant disappeared after it mated, leaving no ootheca, or at least none that I could see.
“As you might imagine, there is a huge amount of mortality,” Raupp said, noting that as the mantis preys, it also is preyed upon, including by birds. “Whether or not she had a shot at laying that ootheca is anybody’s guess.”
© 2016 John A. Bray