failed ootheca hatchings

[Mystymantis]

Ok, so this year I really failed in getting any of my bred Chinese mantis egg cases to hatch, and I am trying to figure out why none of them hatched so I don't have the same problem this year.  So last year I mated several Chinese mantis females, and each female laid a couple of egg cases. I stored the ootheca's in various places, because the last year I had failures in hatchings. So I put some outside in a small container covered in leaves, some in the refrigerator and some in the garage in hopes that some would hopefully hatch. So come Spring I brought them all inside where it is warmer so they would hopefully hatch. But I had no success in any of them hatching. But outside there was an egg case in my garden laid by a mantis outside and it hatched. So I am wondering what I am doing wrong and why they aren't hatching. For 2 years now I have had failures, this year as I said none hatched. So any ideas why the ootheca's are not hatching? could it be not enough humidity?  Or maybe the matings failed? Or the males were unfertile? how many times can a male mate, and how soon can he mate again after he has mated? Perhaps the females were not ready or didn't accept the males even though I saw them engage in copulation. Although it seems unlikely so many would not hatch. I mated the females as I have always, a few weeks after they have turned adults.

Or perhaps the conditions for the egg cases were wrong. But this year I would like to hopefully have some ootheca's hatch next Spring. What is the best way to store Chinese mantis oothecas? I was considering stringing them outside in a garden and bringing them in before they hatch in the Spring. Or maybe it is in the breeding that is causing them not to hatch?

 

[CosbyArt]

My first thoughts are lack of humidity/oxygen, because if a ooth does completely dry out the eggs die (it is a common occurrence with long shipments (about a week or more) especially in heat). The containers should have pin holes (even a single needle sized hole will work) to freely allow air flow exchange, that is what I do with diapaused ooths in my fridge and have no problems. I do also keep carrots and various thing in my bug fridge, so there is always humidity in my fridge with the ooths.

I've read the best method if you plan to place ooths outside, is to place them in closed paper bags. It will keep out pests, but allows air/humidity flow to the ooth(s).

Failed breeding is possible, but with several females unlikely. I haven't heard of a case of a infertile mantid male, but is possible, after all who tests large numbers of male mantids for spermatophore potency (or a single male even).

A mantid male can mate as many times as he wants before he dies. Most keepers use a male to bred females with a few days to a week in between mating. So in that regard that means a male can mate typically about 50 times if he lives 4 months as a adult - in the wild I imagine the number is much higher. The time required by a mantid male between mating to replenish his spermatophore though I do not know the actual time necessary (and searching online doesn't turn up any scientific data).

Most mantid females reach sexual maturity within 3-4 weeks of adulthood (sometimes sooner), and then will call for a male if she is has not been mated yet. So if your females were old enough to mate then there would be no problems, but if they were mated too soon after adulthood they may not have become fertile (the spermatophore would be rejected). Which is why many will re-mate females to ensure they are fertile, and it's said it gives them more eggs per ooths in latter ooths as well.

 

[Mystymantis]

Thanks for all the information!!

I keep the egg cases in small cups with lids that have holes in them, so there was air flow. Which is why I am wondering why none of them hatched as I had them in different places to have at least some with the right humidity.

If I put the ootheca's outside in paper bags how would that work? Paper bags are not very durable, and would get ruined at the first rain. Unless you mean to put them in paper bags inside a shed or something, which would be a problem because I don't have a shed.  Would the garage in paper bags work maybe?

I will probably put some in the refrigerator, like I always do. Is it possible the temperature was too cold in the refrigerator?

 

[hibiscusmile]

Maybe it wasn't fertile at all.

 

[CosbyArt]

Thanks for all the information!!

I keep the egg cases in small cups with lids that have holes in them, so there was air flow. Which is why I am wondering why none of them hatched as I had them in different places to have at least some with the right humidity.

If I put the ootheca's outside in paper bags how would that work? Paper bags are not very durable, and would get ruined at the first rain. Unless you mean to put them in paper bags inside a shed or something, which would be a problem because I don't have a shed.  Would the garage in paper bags work maybe?

I will probably put some in the refrigerator, like I always do. Is it possible the temperature was too cold in the refrigerator?

Sure, your welcome but it doesn't seem like it helped much.

The paper bag would need to be placed somewhere sheltered from the weather directly (rain, snow, etc) - places such as a covered porch, out building/shed, unheated garage, etc. Indeed a garage would be fine if it's unheated and reaches 40 F or below. Ooths regularly withstand temperatures near 0 F or below here in my area, and hatch just fine next year.

 

[Mystymantis]

I was wondering how soon after a female lays her ootheca is best to remove it and place it in the overwintering spot?  A week? or sooner or later?

 

[CosbyArt]

I was wondering how soon after a female lays her ootheca is best to remove it and place it in the overwintering spot?  A week? or sooner or later?

Let a ooth dry for at least 24 hours, I though allow mine to set 2 to 3 days to ensure they are dry (as the extra time doesn't hurt anything).