Praying Mantis; Garden Ally or Deadly Assassin? - gardenstead Skip to content

Praying Mantis; Garden Ally or Deadly Assassin?

Our readers have an ongoing battle with pests in their gardens regardless of where they live. In July we discussed ladybugs being an excellent source of pest control for aphids and how I released 250 of them into my Canadian West Coast garden, but what about other insects? When placing an order for our ladybugs we also ordered praying mantis egg cases. You don’t normally associate praying mantises with Canada but a little over a year ago I read an article regarding someone having purchased a live Christmas tree, brought it inside and a few weeks later having an unpleasant surprise hatching among their Christmas gifts. Dozens and Dozens of baby mantids had hatched after being triggered by the warmth of the family’s fireplace into thinking it was a perfect summer day and time to start their life on the outside world! As you can imagine the poor family was less than impressed by their Christmas day party crashers, but how did a mantid egg end up on a British Columbian Christmas tree? Is their arrival to BC intentional or accidental? Most importantly are they worth the investment next season to try and keep your pests under control?

Brief History on Praying Mantis in BC

In the 1930s the government and local farmers devised a plan to control grasshoppers that were destroying crops. In theory they would release the mantids and hopefully they would establish a colony, getting the grasshoppers and other pests under control. Unfortunately, they did not stick around long after release and they assumed the project failed. Many years later in 1970 they found that some of the original mantids that had been released had reproduced. A population eventually established and now existed in some regions of the province. They have since continued to spread slowly and can now be found widely across the province. Since then people have started buying them and once again attempting to use them for pest control. Some scientists still raise concerns on their impact on local insects, specifically the pollinators. Though the research is limited on this front, in theory they do not get big enough or last long enough to have a significant effect. We do have a species of native flightless mantid in BC to, but again the effect on them is not fully understood or properly studied. They have been sharing a food source and living alongside each other since the 30s and both seem to be doing well.

But how did mine do?

Well that is still up for debate. I received two egg cases from The Bug Lady, and they arrived at the same time as the lady bugs. I decided to stick one outside and try hatching the other inside of a 5g aquarium. The one I put outside I attached to my lilac bush under some leaves but still exposed enough to receive warm sun rays and encourage it to hatch. The second egg case I put on my upper deck for a few weeks but with no sign of progress I contacted the retailer and inquired on what I should do. Was the egg a dud? Or had I done something wrong? They responded quickly and suggested I bring the aquarium inside, the eggs generally need a steady temperature around the low-mid 20s to hatch and it likely was getting too cool in the evenings. So I brought them inside, kept the aquarium light on round the clock and waited….and waited.. and waited….. I then wrote this article with the assumption that they were never hatching only to wake up yesterday morning, start my normal morning routine and nearly die from a heart attack when I realized the egg had not only started hatching but was overflowing with baby mantids. Oh Dear God. My first thought was what did I do! I knew the eggs would hatch 40-400 mantis but I hadn’t really put that into perspective. So realizing there were easily 60 or more mantids already hatched and drying and tons more pouring out of the egg I did the obvious thing and started filming and taking photos. Once I was satisfied with the content I sent my son outside to round up some friends and neighbors. We brought them out and with some hesitation I opened the lid! I had no idea what to expect! Would they fly out at my face? Would they jump out? I wasn’t sure and neither possibility was very appealing but knowing they would become cannibalistic if I left them for too long I had to take a chance. Thankfully they did neither and remained mostly where they were. They were so stationary in fact I realized I was going to have to remove them by hand. Again not thrilled with this reality but knowing I had to start getting them out of the aquarium I started scooping them out 3, 5, 8 at a time. It’s important to note I haven’t even had my first coffee at this point! Saying it was a little unnerving would be an understatement! Once I got going and realized they were actually quite sweet and almost cute it wasn’t too bad. My son was super brave and being very gentle so I started putting them into his hand so he could help spread them across the garden. Meanwhile my daughter who loudly had voiced her dislike for “buggies” was hiding behind our family friend looking rather concerned that we were willingly holding and touching these tiny creepy crawly creatures. Within about 20 minutes we had removed most of the fully hatched and dried mantids. I opted to close the aquarium back up and bring it inside while we waited for the second round of hatchlings to fully emerge and dry out before we tried to move them.

Once the egg was done hatching we brought the rest of them out and repeated the process. I also kept 2 inside for further observation. They are currently enjoying life inside on my windowsill, being hand delivered sugar ants and small flies that we catch for them. I will likely release them next week, but knowing that the ones we let go outside would be nearly impossible to find again I wanted to watch them grow up a bit before I bid farewell to all of the babies. Praying mantis are the single best hide and seek players out there between their camouflage and exceptional stealth skills. Hopefully we see one or two at the end of September presuming they have enough time to mature and mate before dying off in the cooler weather. For those wondering yes technically you can keep them for their entire lives as pets but personally I have one to many creatures and humans needing my attention as it is. So adding two more pets to my menagerie for 6-12 months is not on my to do list!

Final Thoughts

Considering they only hatched yesterday it does present a challenge in writing an official product review. As I have not had a chance to personally witness a decrease in pests in my garden. The eggs were in a great condition upon arrival and when they finally did hatch it was amazing to witness! Incredibly interesting and educational for the kids to see, certainly science project worthy! The hunting abilities of praying mantises is undeniable and so it’s safe to assume that they will do an excellent job feasting on whatever they come across in the garden. They do not discriminate when it comes to their meals though, hence the concern around our local pollinators. The Bug Lady contacts I had spoken with did assure me that they are not likely to go after bees if they have other food sources more easily available, it’s hard to say how successful they will be in my own west coast garden but I am currently very optimistic!

Hatch your own!

If you decide to attempt hatching your own at least you can learn from my mistakes. Make sure you buy from a reputable seller with good reviews. The eggs should arrive dry and cool, ensure you keep them in the fridge until you have settled them into wherever you want them to hatch in. They need to stay at a steady temp and should not go below 20 degrees Celsius. I set mine up in an old 5 gallon and ensured the lid was sealed properly. You can also just use a plastic container with a well-sealing lid, add some moss or paper towel to the bottom of the container and ensure it stays moist but not wet. They take between 3-10weeks to develop and hatch. All of them usually hatch within the hour or two and they are cannibalistic so it’s important to release them or separate them from each other. They will eat small insects to start and as they grow their prey does too. If your intention is to keep it as a pet, you will need fruit flies or another small insect for your new mantid babies. Praying Mantis generally live around a year, so they are not a long-term investment but can certainly be an interesting one!

Have you tried introducing beneficial insects into your garden yet?
yellow petaled flower by elias sorey unsplash

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