Extension News

Praying Mantids Make Great Pets

Praying mantid on branch

Note to media editors: This is the Iowa State University Extension Garden Column for the week of Nov. 16, 2007.


By Laura Jesse
Iowa State University Extension

I write this with a heavy heart, for this week our pet praying mantid has died. She had made her home here in the Plant and Insect Diagnostic Clinic for the past few months. She lived in a nice glass aquarium with mulch in the bottom and a few branches for her to climb on. We fed her with insects we found around the campus. Since her death it has become much lonelier in my office. She wasn’t the best conversationalist, but people came by to visit her all day and bring her offerings of a tasty grasshopper. 

Praying mantids (also commonly known as praying mantis) get their name from the fact that they hold their front legs like they are praying. Their front legs are highly modified for capturing prey and are not used for walking. They are held upright in front of the head and hinge in the middle to open and close like a pocket knife blade against its handle. Along the inside of the leg sections are alternating rows of long and short spines that impale any insect unlucky enough to fall into the mantid's grasp.

Watching her eat was the best part of having a pet praying mantid. She would watch as her prey moved closer and closer. When she felt the prey was close enough she would lunge and grab it. Her folded upraised front legs would extend, snap open, grasp the insect and snap shut in a high-speed blur. She missed sometimes, but once she caught her prey it was a goner. Once she grasped some thing she would just start eating. Often her prey would still be wriggling in her clutches as she coldly began devouring it. She used her small but strong pincers to quickly chop even large prey to bite-sized fragments suitable for swallowing. I should admit that each time I fed her I felt a bit guilty about the fate of the insects and it sort of made me squeamish to watch her eat. 

What about mates as meals? A common misconception is that female mantids always eat their partners during or after mating. In fact, in only one species, the European mantid, is this behavior noted and then only infrequently and while being closely observed in artificial or captive conditions when male mantids can not escape and are eaten by the larger, stronger female. 

Praying mantid adults do not survive the winter in Iowa, but their eggs do. Praying mantids lay an ootheca, which is a cluster of eggs protected by a hard brown substance produced by the female as she lays her eggs. Ootheca collected in the fall will hatch some time during the winter if kept warm.  Many young can emerge from a single ootheca. They are cannibalistic and if not provided with food, they will start eating each other. This may sound cruel, but is a convenient way to limit the number of young you have to raise. Fruit flies make a good food source until the praying mantids are large enough to eat larger insects. Crickets can usually be purchased at pet stores throughout the winter for larger mantids.

We are very excited here in the Clinic because our praying mantid laid eggs before she died. So sometime this winter we should be greeted on a cold morning by a whole aquarium full of hungry babies staring at us through the glass, wondering if we would make a good meal. I can hardly wait.   


Contacts :

Laura Jesse , Plant Pathology, (515) 294-5374, lrahnsen@iastate.edu

Jean McGuire , Extension Communications and Marketing, (515) 294-7033, jmcguire@iastate.edu

There is one photo for this week's column.