We were hosted by a grower who produces certified organic herbs. She explained that her pest management was based largely on biological controls. She proceeded to tell us what worked and what didn't. Needless to say, they were no longer a part of this particular pest management program. These two true stories are what prompted the title of this article.
Mantids are beneficial to the extent that spiders are beneficial.
Mantids will eat virtually anything they can catch, including their siblings and other beneficials. Large mantids, such as the commercially available Chinese mantid, will even catch and eat bees and other pollinators. The family of insects known as Mantidae is large, and there are many fascinating, peculiar, even bizarre mantids in the world. They can be useful subjects to teach about nature and its various mechanisms of balance. They can be a wonder to children.