The European mantis - invasive or welcome?

Upon moving to Kelowna, I was pleasantly surprised to discover a female praying mantis.  While exploring my backyard, I felt a peculiar sensation on my leg; looking down I found it was caused by one of my favourite insects crawling about on my shin.  Somehow I had managed to pick it up as I was surveying my newly acquired kingdom.

As a boy in Ontario, I regularly saw them and would collect and observe them for long periods of time - one of the few things able to hold my somewhat narrow attention span.  Their size, agility, and relative calmness when being held were all-captivating.  The males are green and have wings; the females are brown but are devoid of any flying appendages.  Mantids have a singular ability to capture and devour prey, usually other insects, another behaviour I frequently observed in my youth.

The European mantis was brought to New Youk by accident in 1899.  Like so many other introduced species, it thrived and spread throughout the eastern US and Canada.  During the 1930's it was intentionally released in BC's Okanagan and Shuswap as an attempt to exert biological control over crop pests.  The experiment failed in the sense that much of the population died out.  There is still a self-sustaining population present throughout the southern and central Okanagan.

Some of the criteria for considering a species invasive is its ability to grow rapidly, take over natural populations, and do considerable environmental damage.  Evidence shows that, in BC, the European praying mantis does none of these things.  Their numbers are far from explosive and they consume more pests than they do beneficial insects.  They are remarkably strong for their size and are capable of catching humming birds (see video - may be upsetting) and larger prey items.  

Although they will take beneficial insects, such as bees, they do not pose a significant threat to these populations.  Likewise, their ability to control pests is somewhat limited.  Overall, I find their presence a welcome addition to the biodiversity found here in the Okanagan.

Thanks for reading.   www.ericspix.com