European Praying Mantis

 

If you’re a grasshopper this mantis  could be the last thing you see.  An ambush predator, mantises snatch their prey in those spiny forearms, and eat them alive.  European praying mantises are not native to our area but have become quite common.  They likely were introduced to help control pests.  In the past,  Fred Meyer has   sold mantis egg cases  in their garden stores.  Their value for controlling garden pests is questionable.  They disperse  after hatching, are cannibals, and eat good insects such as honey bees.

They hatch in spring, and after several molts become winged adults around the first of September.  Mantises are well known for their cannibalistic tendencies with many articles and nature documentaries showing the female devouring her smaller mate.  It may not be quite like that.  After all, a female mantis must at least have a mate if she is to have offspring and to do that she has to allow a male to climb onto her back.  Mating takes a long time, several hours.

The Nazarene Church across the street from  me used to have floodlights to light up the east side of the building.  The bright lights would attract the newly emerged adult mantises the first week of September.  A few years ago I collected three males and a female from the side of the church.  I put them all in a Styrofoam ice chest.  The next day, when I took off the lid I found all three males on the female’s back.  One was on the center and the other two were off to each side.  No body was eating anybody and they all were quiet.  Later, when I looked again,  one of the males was mating with the female and the other two were still in the chest but no longer with the female.  The virgin female likely puts  out a pheromone that helps males find her.  It may attenuate not only her behavior but that of the males as well.  Suppressing predatory behavior then facilitates successful mating.  After mating, the female can resume her predatory behavior and if the male hangs around too long she may eat him.

I’ve had the female in the above photo for a week or so.  She deposited an egg case on the side of a glass container.  It should contain over 100 eggs or so.  If you look carefully as you walk around Ridgefield, you may find one.  Ones on fences and fence posts are easier to find.  They are about one inch long.   Next spring the young will wriggle out of the egg case and dangle on slender threads as  their bodies harden.  Then, they need to get away from each other.

Contributed by Paul Snoey

 

 

 

About Paul Snoey

I have a degree in Biology and Environmental Science from WSU Vancouver
I am very fond of Gee Creek and Allen Canyon Creek and do a lot of volunteer work to restore these creeks.

Leave a Reply