More Praying Mantis Egg Cases
By now you may have guessed that I’m rather fond of praying mantids. There’s something about their size (unusually large for this part of the world), their ferocity as a predator (watching one systematically bash a bumble bee against the shed to subdue it was pretty wild!), their “praying” position, and their endless patience (they’ll stay motionless for ages, just waiting for a potential meal to come along) that, to me, is simply fascinating. But what I like best is what they do to the population of insect pests in the garden – the praying mantids almost single-handedly eliminate serious pest problems in my back yard.
I garden organically - no chemicals at all (Well, actually, that’s not entirely true – I have to admit to using a fungicide for black spot on my roses. I grow mostly shrub roses that don’t get black spot, but a couple of the climbers do and I can’t bring myself to get rid of them.). So, ok, aside from the roses, I don’t use any chemicals. So anything that helps me combat insect pests is welcome in my garden. And praying mantids fit the bill. Now I do realize that they’re indiscriminate predators – they do eat beneficial insects too (like that poor bumble bee I saw being whacked to death). But, overall, they take out far more bad insects than good ones. Since the praying mantids took up residence in my garden a couple of years ago, I haven’t had any problems with pesky insects (other than one aphid infestation on a heliopsis).
To encourage them to stay, I provide a diversity of plants (which is simply good gardening practice anyway) and ensure that there are plants with sturdy stems for them to lay their eggs on. The female mantis lays the eggs in a foam substance that quickly hardens into a golf ball sized, brownish ball. It reminds me of the spray foam that you use around windows and in cracks in your house. The egg case is quite hard – if you give it a squeeze you’ll find that there’s not much give and it won’t crack. It can be distinguished from other types of egg cases by the very distinctive ‘zipper’ at the bottom of the case. In the photo above you can just see what looks like a ridge or line in the flattened area at the bottom of the egg case.
Just last week, as I was doing a bit of fall clean up in the back yard, I noticed a new praying mantis egg case on a salvia (photo above). The egg cases are difficult to see from a distance as they blend in with the surrounding leaves and stems. If you simply cut down dead plants in the fall, you may very well be cutting down (and throwing away / composting) egg cases. So, this fall, as you tidy up around the garden, take a closer look at plant stems – you just may find that a praying mantis has left you a gift that could help keep your garden pest-free next summer.
