Question about Chinese Praying Mantis Egg Cases

[Colorado Ts]

I ordered a group of Chinese Praying Mantis Egg Cases. This was intended as a Biology activity for my grandsons. We were going to hatch the egg cases, grow the baby mantids out a bit and then release them into the gardens in the backyard.

They arrived via USPS late yesterday; tracking was never updated, the box is clearly labeled “Avoid Mailbox”...so they spent the night in the mailbox. It got down to about 27 degrees last night. My concern is that the egg cases may have frozen and died.

You guys know this better than I...what are your thoughts?

 

[chanda]

They should be fine. When they are laid in the wild, they routinely experience cold - sometimes even freezing - temperatures. The case is sufficient to protect them while they overwinter, and they'll hatch when the temperatures rise and become consistently warm.

 

[Colorado Ts]

Thank you for your post. The package is in the fridge, waiting for the grand kiddos.

We were planning to hatch them in 32oz deli cups, with ventilated lids. And the young were going to be fed tiny B.lateralis roaches or even springtails...if they are really tiny.

 

[Colorado Ts]

The grand kiddos and I setup the hatchers for the praying mantis egg cases. We are using 32 oz deli cups with ventilated lids. There are 10 egg cases. The ambient temperature in the house is ~70 degrees.

The hatchers are setup on the top shelf of my Invertebrate display cabinet. Its close to the lights so that I will more easily see when hatching occurs. I’ve started a journal on this project to that with future hatches, I’ll better be able to tell what’s normal and what’s not.

My plan is to feed springtails to the mantids when they hatch out. I have 6 cultures of springtails going, they look healthy and are growing well.

So how do I feed the mantids? Is there a certain size when I start feeding? Or should I start right away?

Any suggestions would be greatly appreciated.

 

[chanda]

My plan is to feed springtails to the mantids when they hatch out. I have 6 cultures of springtails going, they look healthy and are growing well.

So how do I feed the mantids? Is there a certain size when I start feeding? Or should I start right away?

Any suggestions would be greatly appreciated.

You are going to have a LOT of baby mantises! They will start eating pretty quickly after hatching - and there will be a lot of cannibalism if you keep them communally. Those cups are fine for keeping the oothecae in until it's time to hatch - but after that, you'll have hundreds of mantises in each cup, and those cups will be way too small. When I've had baby mantises, I usually release a bunch of them into my yard right away - just to reduce the numbers to prevent widespread cannibalism. I transfer the remaining babies to larger enclosures - such as mesh pop-up butterfly cages - with plenty of sticks, fake plants/vines, or vertical/diagonal cork slabs for the nymphs to climb, hide in, and hang from while molting. (To transfer the nymphs, just remove the lid from the cup or open it slightly, then put it in the bottom of the larger enclosure, and let the mantises "transfer" themselves.)

As for feeding them, I've never tried springtails. The newly-hatched nymphs may take them, but springtails are pretty small and Chinese mantises are bigger than many other mantis nymphs, even as hatchlings, and they grow quickly. As the nymphs grow, they'll need larger prey. I've usually started mine out on large fruit flies (D. hydei) and then worked up to crickets as they grow. The fruit flies are ideal feeders because they climb the sticks and other decor and the sides of the enclosures, going right up to the mantises, while the springtails are more likely to be hiding down in the substrate, where it will be harder for the mantises to get them.

It sounds like a fun project for the grandkids! But be prepared to have to explain the cannibalism, because it will happen - and the kids will probably notice. Kids are very observant.

@Colorado Ts: Edited to add: If you want to prevent cannibalism, then separate the nymphs. Release most of them outdoors - then put one nymph in each deli cup, with some sticks, fake plants, or other decor.

Also, to make feedings easier - and escapes less likely - if you do decide to keep nymphs in deli cups, cut a hole in the lid of each cup, then cut a piece of sponge to fit the hole. That way, all you have to do to feed them is pull out the sponge and drop feeders down the hole, then put the sponge back in place. I usually cut the holes around 1/2 to 3/4 inch in diameter, and the sponge is slightly larger than the hole to ensure a tight fit.

 

[Colorado Ts]

Chanda you are awesome...thank you so much.

I ordered two butterfly cages from amazon...thank you for the heads up.

Fruit flies.....No...NOT fruit flies!!!!!

I've used fruit flies for genetic studies in labs with my students...dang, they get everywhere. Okay fruit flies it is then.... probably turn most of the mantids loose right away and keep a small group so that the kids can watch them grow out.

Again...thank you so much.

 

[Colorado Ts]

You are going to have a LOT of baby mantises! They will start eating pretty quickly after hatching - and there will be a lot of cannibalism if you keep them communally. Those cups are fine for keeping the oothecae in until it's time to hatch - but after that, you'll have hundreds of mantises in each cup, and those cups will be way too small. When I've had baby mantises, I usually release a bunch of them into my yard right away - just to reduce the numbers to prevent widespread cannibalism. I transfer the remaining babies to larger enclosures - such as mesh pop-up butterfly cages - with plenty of sticks, fake plants/vines, or vertical/diagonal cork slabs for the nymphs to climb, hide in, and hang from while molting. (To transfer the nymphs, just remove the lid from the cup or open it slightly, then put it in the bottom of the larger enclosure, and let the mantises "transfer" themselves.)

As for feeding them, I've never tried springtails. The newly-hatched nymphs may take them, but springtails are pretty small and Chinese mantises are bigger than many other mantis nymphs, even as hatchlings, and they grow quickly. As the nymphs grow, they'll need larger prey. I've usually started mine out on large fruit flies (D. hydei) and then worked up to crickets as they grow. The fruit flies are ideal feeders because they climb the sticks and other decor and the sides of the enclosures, going right up to the mantises, while the springtails are more likely to be hiding down in the substrate, where it will be harder for the mantises to get them.

It sounds like a fun project for the grandkids! But be prepared to have to explain the cannibalism, because it will happen - and the kids will probably notice. Kids are very observant.

@Colorado Ts: Edited to add: If you want to prevent cannibalism, then separate the nymphs. Release most of them outdoors - then put one nymph in each deli cup, with some sticks, fake plants, or other decor.

Also, to make feedings easier - and escapes less likely - if you do decide to keep nymphs in deli cups, cut a hole in the lid of each cup, then cut a piece of sponge to fit the hole. That way, all you have to do to feed them is pull out the sponge and drop feeders down the hole, then put the sponge back in place. I usually cut the holes around 1/2 to 3/4 inch in diameter, and the sponge is slightly larger than the hole to ensure a tight fit.

Yeah this will be nuts...I ordered these cases originally to use in my biology classes with my students...well we are closed and online for now. So yeah...lots of babies...

You've been wonderful in your advice...the grandkids have already asked me five times when they will hatch, based on my reading I'm guessing 10-14 days. So we'll see.

 

[chanda]

Chanda you are awesome...thank you so much.

I ordered two butterfly cages from amazon...thank you for the heads up.

Fruit flies.....No...NOT fruit flies!!!!!

I've used fruit flies for genetic studies in labs with my students...dang, they get everywhere. Okay fruit flies it is then.... probably turn most of the mantids loosright away and keep a small group so that the kids can watch them grow out.

Again...thank you so much.

The hydei aren't too bad - they're flightless, so they don't escape as readily as the winged varieties, they're bigger than the other commonly cultivated varieties, and many pet stores (particularly those that cater to inverts, dart frogs, or other exotics) will have cultures available.

When feeding them off, what I find works well to prevent escapes is to put an empty plastic bag (those ones the crickets come in) into an empty vase or jar, then tap the sides of the fruit fly culture to knock the flies down from the top before removing the lid. Tilt the fruit fly culture over the open plastic bag. (Just tilt it a little - it should remain slightly upright, not horizontal or inverted.) Shake the culture gently as the flies climb toward the opening, knocking them into the bag. Once you have enough flies in the bag, tap the sides of the culture to knock the flies back down and put the lid back on. You may also have to tap or jiggle the bag periodically, to knock back the flies that are trying to climb out. Once you get the flies in the bag, grasp and pull the corners to gently flatten the bag, then you can pour the flies into your enclosures, using the fold in the side of the bag as a funnel.

 

[chanda]

I ordered two butterfly cages from amazon...thank you for the heads up.

When it comes to the butterfly cages, there are some with really fine mesh and zippered doors that work really well for mantises and keep the fruit flies contained - and others with much looser mesh and/or a flap closure with a little velcro tab that allow the fruit flies to get out. The ones I like are the square ones that have the finer mesh and the entire side zips open. (Because the flies climb, they tend to congregate at the top - so a top-opening enclosure is likely to have more escapes when you try to open it, while a side-opening cage tends to be more secure.) The round ones - because they are intended for butterflies and caterpillars - often have the looser mesh with larger holes that the flies can escape through, and sometimes also have the flap-type lid that can leave a small gap around the edges.

 

[Colorado Ts]

When it comes to the butterfly cages, there are some with really fine mesh and zippered doors that work really well for mantises and keep the fruit flies contained - and others with much looser mesh and/or a flap closure with a little velcro tab that allow the fruit flies to get out. The ones I like are the square ones that have the finer mesh and the entire side zips open. (Because the flies climb, they tend to congregate at the top - so a top-opening enclosure is likely to have more escapes when you try to open it, while a side-opening cage tends to be more secure.) The round ones - because they are intended for butterflies and caterpillars - often have the looser mesh with larger holes that the flies can escape through, and sometimes also have the flap-type lid that can leave a small gap around the edges.

Crap...I didn't even think that there would be issues with the fruit-flies escaping.

I ordered 2 of the taller units, with the side zippers. Hopefully no issues. When I researched this project for my Biology class, those were the ones mentioned, this was originally intended to be a project for my Biology students. So at least the cases won't be going to waste. And I ordered the fruit fly culture with an expansion pack to make up to 10 cultures...overkill, but I'll just plan on using the kits in my Biology classes next year.

I went with the taller butterfly cage units, so that the grandkids could take branches and clay pots and make climbing features that will stand up inside the cages, for the nymphs. Or we could buy 2 potted plants or small potted bushes to use as climbing features.

We talked about our family project over lunch today...we'll hatch out the egg cases, release most of the mantids into the backyard, once they hatch. Then from each Delicup Hatcher, we'll keep a couple nymphs in the butterfly cages. So keeping 2-3 nymphs per delicup...still provides us with 20-30 nymphs. I put half and half into each butterfly cage, and then each grandchild has their own group to watch and maintain.

 

[mantisfan101]

That's gonna be a lot of baby mantids; at least a thousand or so. Springtails are kind of out of the question since they take too long to reproduce and even then you're gonna need quite a lot of fruit fly cultures. Also I'd maybe add a small container with some fruit or fly media in there so any flies that manage to escape can continue to feed. Also there will inevitably be escapees(both mantids and flies) and hopefully you'll be able to release the vast majority of the mantids. When they do hatch I'd suggest getting one of those giant pop-up laundry hampers(in this case, the biggest you can find) and put those in there as you will have a lot of babies.

 

[Colorado Ts]

Here we are 22 April 2020, and the first egg sac has hatched. I didn’t even try to count them...estimated...I’m guessing low 200’s. The egg case hatched in 17 days. The average room temperature was 70 degrees during the day dipping to 62 degrees. My wife has programmed the furnace in our house to adjust to a lower temperature at night.

I ordered in a culture of flightless fruit-flies, that had been recommended...but the culture was non-viable. Working with the shipper has been ridiculous, but after 8 days they finally relented and shipped a replacement culture. The replacement culture is set to arrive TOMORROW!!!

So I do not have any fruit flies to feed these little guys.

Future Note: Get the fruit flies cultures established and producing, BEFORE I start the egg cases incubating. Such a simple concept, would've been nice. Though I'd still not have been able to start this project yet....

 

[Colorado Ts]

Without prey items the tiny mantids would just cannibalize each other. So my grandsons and I took them outside and released them in the landscaping of my front yard. I would have much rather to have fed these tiny creatures and raised them to about 2”-3” or so before release, but my replacement order of fruit-flies won’t arrive until tomorrow...dang.

I’m pretty sure that I’m probably not going to be able to get the fruit-flies going before the other egg sacs follow suit and start hatching. So I might just work my way through these egg sacs, one by one as they hatch...get my fruit flies going...then order another set of egg sacs and start over.

...at any rate, very exciting to have this small bit of success to share with all of you.

 

[Colorado Ts]

Impromptu Dissection



Young kiddos are so curious. My grandkids were really curious about what the inside of an egg sac looks like...so we opened it up.

If you look really close you can see where a couple of eggs had not hatched yet. I’m wondering if they all hatch at once and these unhatched eggs were non-viable. Or maybe they would have hatched out over time, at a later date.



You can see where each one of the individual eggs fit into the structure. The grand-kiddos each got out their magnifying glasses and looked the halves over very closely...asked lots of questions...then went back outside to see if they could find any more of the young Praying Mantis hatchlings.

 

[Colorado Ts]

So 9 more egg sacs to go...very fun project to do with the kiddos this spring.

 

[KenD]

View attachment 341440

Without prey items the tiny mantids would just cannibalize each other. So my grandsons and I took them outside and released them in the landscaping of my front yard. I would have much rather to have fed these tiny creatures and raised them to about 2”-3” or so before release, but my replacement order of fruit-flies won’t arrive until tomorrow...dang.

I’m pretty sure that I’m probably not going to be able to get the fruit-flies going before the other egg sacs follow suit and start hatching. So I might just work my way through these egg sacs, one by one as they hatch...get my fruit flies going...then order another set of egg sacs and start over.

...at any rate, very exciting to have this small bit of success to share with all of you.

I'm a little late here, but for the next hatchlings: don't release them outside if they're not endemic to the area.

 

[Colorado Ts]

I'm a little late here, but for the next hatchlings: don't release them outside if they're not endemic to the area.

Here is the US these Mantids are sold commercially as a biological alternative to using pesticides. So yeah...Not a concern.

 

[MasterOogway]

They're not native to the US, but they're naturalized and de-regulated because they're already *everywhere*. One of the only non-native bugs you probably don't have to worry a great deal about releasing.

 

[Colorado Ts]

Since the first egg case hatched, None of the other 9 egg cases have hatched. I’m wondering if they are all non-viable, that doesn't bode well for the seller to be selling egg cases that are 90% useless.

 

[mantisfan101]

It can take a while, also since most of the eggs are wild caught there’s really no telling if they’ll hatch or not.