Depressing/Interesting thought

[PhilinYuma]

I just posted on Frey's feedback thread about the high hatch success that I have had with her ooths and the consistently poor success with ooths that I have bought in the US over the past few months.

Here is a depressing (or interesting, depending on how you look at it) question. Is it possible that we have developed strains of exotic mantids in the U.S. whose ooths hatch more readily under very different conditions from those in the tropics from whence they came? In Europe, there is a strong tendency, at least in recent years, for "serious" mantis breeders to use an incubator for their ooths where they can control temperature and relative humidity.

I am sure that I am not the only one over here to use something similar. 'lectric Blues eyes(!) built a glass incubator several years ago, I think that Sporeworld uses a method similar to mine and Frederick Prete of the Prete Book published a description of a mass incubator in the early nineties that used air driven through a wash bottle as a humidifier.

I think, though, that the vast majority of members of this forum keep their ooths ion a covered pot at room temp and spray it "once or twice a week" with a spray bottle.It is possible that we have developed strains of mantids that are used to this treatment, since those ooths that could not tolerate the low temp/humidity would not have hatched, and that now, they do poorly in the more natural conditions of 80F and 80%RH, which usually require the use of a lamp and a humidifier over here.

So please, could members who buy European and U.S. ooths tell which of the two basic hatching methods you use, and whether or not you have greater success with either U.S. or imported ooths?

I think that I shall pull all of my unhatched US produced, exotic ooths, leave them at room temp, give them an occasional spritz and see what happens.

 

[sporeworld]

An interesting thought, indeed.

I've got to think that using an incubator MUST be better, ASSUMING we know how to properly dial it in.

I'm curious... do you cut open the ooths after a certain time? If so, have you noticed them too dry? Too wet? to unfertilized? Whay are they not hatching? Are their dried or molded nymphs/eggs inside?

Of ooths sent to me from others, I'm almost certain I've had more hatch IN transit, than after. But from my own stock (that I KNOW were fertilized, and didn't undergo any extremes from shipping), it's darn near 100% success. Ghosts, Creos, Gongy's, Iris, Chinese, Europeans, Statilia, Mios, ... and on and on.

So what would be a good experiment? To take a really long Creo ooth, cut it into a number of peices, and put each in a different environment? Hard to get controls...

 

[Peter Clausen]

That's an interesting topic, Phil. My contributing thoughts originate in personally not knowing what exactly is happening out there in the hobby.

1. What percentage of the oothecae hatching on US soil are products of multi-generational "American" stock? How many generations does it take to produce a "strain" (or prove one)? Does anybody have reliable data on incub. temps and humidity levels for their US produced mantises?

2. What constitutes a successful vs. failed hatching? I've seen a lot of partial hatches where maybe only six mantises come out of an ootheca. A few live to reproduce, but it seems they were likely more humid/less dry than the other end of the ooth in these micro-habitats we incubate them in (often with that poly-fiber lid with huge holes covered up by paper-fabric stuff).

For example, I received 3 ghost mantis oothecae from Rebecca/Mantisplace in July. They were dated as having been laid in June. I kept them in my water dragon's 85 degree tank (it sets at 85 degrees on the floor of the 100 gallon tank, while it's warmer up near the lights and heat emitters, and nighttime temps are around 73). I spray them every day or two. Then, having left town for the weekend, I took them out of the tank (occasionally the water dragon will knock the 32 ounce cup down and might get excited if left alone with hatching mantises for a couple days). So, when I returned from my trip the first ooth had hatched in 73 degree temps. on a rack above a bearded dragon cage. My point in mentioning this is that I have a system, and though it's not very "serious", it works just fine. But, we never know what conditions ooths were kept in prior to shipping and during transit.

3. Another consideration is the number of foreign dealers vs. domestic dealers and their integrity in terms of how well they care for something they are selling (or giving away).

Yours is a tough question to answer, I think, without really gathering some data.

In my experience the ooths are less likely to develop properly and hatch if they aren't kept warm enough. There are a few things that can go wrong and by offering temps. on the low side, hatching is prolonged. The more it is delayed, the chances of something going wrong are increased. For example, if humidity is not balanced with heat, they will dry out and either die or result in partial hatches.

Budwings and maybe ghosts seem like they'd be a good candidate species for your theory. I'm not sure what other species might be raised generationally and not regularly imported.

 

[sporeworld]

I like the idea of splitting a ghost ooth, since you can sort of see how many nymphs to expect. I wish I had done that when I had all those creo ooths.

So, are you (Phil) suggesting that we may have selectively bred mantids that thrive in a differnet temp/rh environment...? Or is it that our US stock is do dimished in quality that it continues to produce fewer nymphs?

 

[PhilinYuma]

I like the idea of splitting a ghost ooth, since you can sort of see how many nymphs to expect. I wish I had done that when I had all those creo ooths.

So, are you (Phil) suggesting that we may have selectively bred mantids that thrive in a differnet temp/rh environment...? Or is it that our US stock is do dimished in quality that it continues to produce fewer nymphs?

Yes, i wonder if we haven't selectively bred mantids from ooths that tolerated reduced temp and humidity compared with what obtains in the wild. I think that folks like yourself can state which of the two major hatching strategies they use, 80F/80% or so in a controlled environment or room temp humidity with an occasional (and infinitely variable!) spritz, and then determine if European or US bought ooths do better with their method or have the same success. Then, if there enough responses, we shall at least know whether to follow the matter further.

You ask if I cut open ooths. As a young teen (17) I served the Queen (God Bless Her) as an infantryman using edged weapons. As an RN, I would stick a 19G needle into the femoral artery of screaming babies (for arterial blood gasses) when the resident couldn't stand sticking the baby any more ("You look a little tired, doctor, would you like me to try my luck?" Bingo!). I never turned a hair, but I am seriously reluctant to cut open an ooth, even though i know that it is a good idea, in case I offend The Great Mantis Goddess (BbHN). Go figure!

 

[Rick]

Or maybe it just shows how adaptable these creatures really are.

 

[ismart]

If some possible experiments were done. Would we be using the first ooths of gravid females for comparison? The reason i ask is the first ooth verses the seventh ooth will definitely have different hatch rates no matter how they are kept. What species would be a better canidate for any such experiments? Temperate, or tropical?

@Phil: I consider you quite an intelligent man. If you could take some time, and come up with some possible experiments. I would be more than happy to participate in some of them. I'm no scientist, but i think it would be kinda fun!

 

[sporeworld]

IF, we're selectively breeding, it would seem we were chosing nymphs that could ALSO hatch under our (worse?) US standards. That would produce STRONGER stock, right? But we're reporting here a REDUCED hatch rate.

So, if we use Creos (abundant, robust, cheap) and take a single ooth. We assume the front and back are no more or less fertile (which I have no idea if THAT's even true), and cut it into, say, 5 equal parts. Plop each part into identical "pots" with controlled heat and humidity, starting with the prevailing "best" of both.

Experiment #1: Vary just the HEAT and monitor the results.

Experiment #2: Vary just the HUMDITY and monitor the results.

(Here's where I'm going to drop the ball). If we find, through more identical experiments, that there is a CLEAR favorite, do we do another round of experiments to find the optimal combined range of both? Or have we just allowed "weaker" stock to survive through optimal conditions, instead of selectively breeding for those more tollerant of sloppy husbandry?

Just to throw another twist in there, I'm becoming more and more convinced that the varying humidity (and maybe temp) are just as critical. That a drying and soaking regimine might be better than a constant RH/temp. Is there any reason to suspect that the ooths NEEDS occassional droplets of water, not just an ambient RH? Or that condensation forms INSIDE the ooth, that benefits the egg development?

 

[Malti]

What about this experiment goes international?

take the same species of mantis, same age. say exchange 2nd and 4th ooth, and hatch all 4 ( so each participant gets their own 1,3 ooths and 2,4 of the other) then 1+3 is compared to 2+4...and maybe use the temp controlled method or the open method (depends what criteria are chosen)

 

[Gill]

I have kept Polyspilota aeruginosa for 4 years now, first year terrific hatch next generation poor, then an even poorer one. Original breeding event of 3rd gen stock was just one mating. Added new blood and terrific hatches again. I think it might be that if there are not enough breeding events in previous generations then ooth fertility declines. We have seen that in the UK with the last Christmas boxer mantises as well I think as there is evidence that people mated and got ooths for both Ephestiasula pictipes and Hestiasula brunneriana .

A lot of the 'European stock you have received mightnot had many generations in captivity or they might have had more original breeding events, ie not all the current stock from one original ooth two generations before.

 

[d17oug18]

In my opinion, captive breed mantis are not breed on there selective strengths. But by how pretty they are, because we can just keep them constantly fed and under the best treatments the weakest mantises can thrive. I imagine that in the wild, only the females that can lay alot of nymphed ooths with as little food as possible last the longest(generational). Which would explain why the first few wild caught Ooth generations lay so many under captivity not because we took good care of them but because there wild bred to be extra fertile. Then we start giving away some, some die of from mis-caring, and they become less reproductive... Its an easy question to me and i think i answered it well, no experiment needed =)

 

[PhilinYuma]

Well, this thread has done several good things for me, but I suspect that my original proposal was not made clearly, since though several people have addressed more sophisticated aspects of this issue, no one has answered my original question! Let's try again.

I incubate all of my ooths at about 80F/80%RH during the day. I have noticed that my imported exotic ooths from Europe tend to have a high percentage (nearly 100%) of success under these conditions but that i have had a high rate of failures with US produced ooths. I am talking about hatching/non hatching events here, not hatches with a small number of nymphs.

My numbers are too small to support anything more than a guess, but I have wondered if European ooths produced from females who were hatched under controlled high temp/humidity conditions will tend to hatch under similar conditions or fail to hatch when subjected to the common American hatching method of room temp and an occasional spritz. If some ooths did hatch under these conditions, though, and as Rick says, mantids are remarkably adaptable, then their offspring would be more likely to produce ooths that also hatched under these conditions. The model for such a phenomenon is "natural selection", not artificial selective breeding, since the breeder has no control over the process.

So my question to members is: 1)Do you raise yr ooths under controlled high temp/humidity or "room temp and spritz" conditions? and 2) do you find any difference between the hatch success of domestically or European raised exotic (not U.S. native) ooths?

There are a lot of facts that oppose my guess. One obvious one is that i don't know if all breeders exporting ooths from Europe use the high temp/humidity method, though i know that it is much more common there than here. Also, some of Frey's ooths were WC, like the NZ ooths, and still hatched under my system. Also, I have received Emails from several U.S. breeders whom I hold in high regard, saying that the ooths they asent me may have been infertile. This would most certainly not stop me from continuing to trade with them.

Finally, Gill's interesting post raises an important issue about hatch failure that is not the subject of this thread. I find it so interesting that I shall take the liberty of opening a new thread on the subject to avoid introducing a new component to this discussion.

Meanwhile, I must do the washing up and hey, the sun here just passed over the yard arm!

 

[catfish]

Sounds fascinating. And unintended change in captivity is certainly possible... like the angelfish who no longer have the instinct to look after their eggs and fry, or the changes in pH tolerance in many acidophilic aquarium fishes.