What do you say?

[sidewinder]

Sidewinder,A taxonomist shouldn't have any problems. This is simply an adaptation to environment. M. religiosa is native to a huge area with multiple climates. The population found in Africa looks identical to those found in central Europe. Now, over a huge span of time, it is possible that the 2 populations could evolve into 2 different species. But they are currently the same species. A question I would ask is if you cross members of both populations, will the ooth require a diapause? Is it possible for say half the eggs to hatch without a diapause while the others require a diapause?

Hypoponera,

If the oothecae of Mantis religiosa in central Europe require a period of colder temperatures to break diapause and the oothecae of M. religiosa in Africa do not need a diapause at all, doesn't this adaption imply that the M. religiosa in Africa have evolved into a subspecies (or vice versa)? The results of interbreeding the two and what their oothecae require would be extremely interesting but that wouldn't have any bearing on whether or not the African examples are a subspecies of M. religiosa, would it? Subspecies can often interbreed successfully.

A species changing from requiring a diapause to not requiring one is not a simple adaption.

Isn't this different than a species, such as Tenodera sinensis, that support a diapause but do not require one?

Interesting stuff.....

Scott

 

[joossa]

Hypoponera,If the oothecae of Mantis religiosa in central Europe require a period of colder temperatures to break diapause and the oothecae of M. religiosa in Africa do not need a diapause at all, doesn't this adaption imply that the M. religiosa in Africa have evolved into a subspecies (or vice versa)? The results of interbreeding the two and what their oothecae require would be extremely interesting but that wouldn't have any bearing on whether or not the African examples are a subspecies of M. religiosa, would it? Subspecies can often interbreed successfully.

A species changing from requiring a diapause to not requiring one is not a simple adaption.

Isn't this different than a species, such as Tenodera sinensis, that support a diapause but do not require one?

Interesting stuff.....

Scott

Ahh... the joys and beautiful wonders of taxonomy and taxonomic composition.

This is all very interesting, BTW!

 

[Hypoponera]

Hey Salomonis,

Thanks for pointing out the name change. I was trying to figure out how I messed that up!

You are now entering the weird and wacky world of taxonomy. What makes a species unique from another? There is an ant species complex composed of 10+ different species that can only be told apart by genetic analysis. They are externally identical. No one has been able to tell me if they will breed as each species is in a different section of Europe. So at what point do we say one is a species, sub-species, or all one species with wide genetic differences?

It is possible that the southern population has simply lost the requirement. With no cold period to work with, only those specimens who lacked the genetic trait requiring the diapause would have survived in the south. This "ability" would have been considered a useless trait in the northern part of the range. So if a mutation occured and the genes for diapause were turned off, the animal could survive without cold weather. That does not mean the mantid can not survive winter in the north. A portion of the population with the non-diapause genes would grow and pass the gene on. Then some migrate southward.

It also might be possible that the gene for diapause is dominent and the gene for non-diapause is recesive. Maybe the poulation in the south has breed out the dominent gene in favor for the recesive. Much like eye color in humans. Most of the people I know in Norway had blue eyes. Blue is recesive. When I moved to Italy, the common eye color was brown. Brown is dominent But having blue eyes does not put you in a different species catagory from someone with brown or green eyes.

Am I make any sense? If so, please explain it to me! I am starting to give myself a headache!

 

[sidewinder]

Hypoponera,

For the central European Mantis religiosa to require diapause while the African M. religiosa does not, tells me that the two are genetically different in a significant way.

This is not a simple difference either. For example, if the central European M. religiosa did not require a diapause, the species could die out if summer lasted longer than usual. The oothecae could incubate and hatch. Then, when winter arrived, all the young mantids would die. Conversely, if a the African M. religiosa required a diapause, they might never hatch.

Basically, neither population could afford to be different than they are in regards to diapause.

To me, that means they are different species or a species and a subspecies. Maybe:

Mantis religiosa

Mantis religiosa okhidiapausis



But hey, what do I know?

Scott

 

[Orin]

Taiwan still has seasons, there's no reason to believe that a very specific temperature range is required (consider the range of temperatures across the species range in just the US or Europe).

 

[sidewinder]

Orin,

Taiwan has a marine tropical climate which tells us the mean temperature is above 64.4 °F (18.0 °C) all year long. There is no way the climate in Taiwan would break diapause for a central or northern European Mantis religiosa.

Mantis religiosa is also present in African countries. One such country is Ghana which is few degrees north of the Equator. If M. religiosa in Ghana required a diapause, it would die out.

The only way M. religiosa makes any sense in Taiwan and Ghana is if the populations in both countries do not require diapause. Mantis religiosa in central or northern Europe absolutely require a period of colder temperatures to break diapause.

Scott

 

[kamakiri]

It's entirely possible that diapause is triggered by a relatively high temperature...say something like 65 or 68 degrees F.

 

[sidewinder]

Orin and kamakiri,

Did you guys read this:

I had questions about this awhile ago when Fisherman_Brazil first told me about M.religiosa in Taiwan. I sent an email about it to Dr. Yager and got this in response:"Because mantises are primarily tropical in distribution, the issue of diapause doesn't come up often. Even M. religiosa, which needs diapause over some of its range, does not in others (southern Europe, Africa)."

So there are some populations of M. religiosa that do not require a diapause. Quite possible that a "southern" poulation has set up in Taiwan. So yes, it is quite possible for M. religiosa to survive and breed in Taiwan.

Dr. Yager is the Dr. David Yager that contributed to the book "The Praying Mantids". He knows what he is talking about. If he says there are M. religiosa in parts of the world that don't need a diapause, I would tend to believe him.

Scott

 

[MantidLord]

Wish I could contact this guy. But how do any of you suppose that this came to be? Do you believe that it some how adapted to not require dispause? Or that it will potentially "evolve" into a completely different species like someone previously though?

 

[sidewinder]

MantidLord,

Let's assume for a moment that Dr. David Yager is correct and Mantis religiosa in tropical regions do not require a diapause for their oothecae to hatch. Either the M. religiosa in tropical regions adapted to not require a diapause or the M. religiosa in temperate regions adapted to require one.

Keep in mind that the adaption to require a diapause is quite important in temperate regions. Without the diapause, oothecae subjected to extended warm temperatures would hatch late in the season and the nymphs would die at the first frost. This would decimate the species in the areas affected and would eventually cause extinction.

In my mind, a test to determine if the tropical and temperate populations of M. religiosa are the same species would be to take an ootheca from each and place it in the others habitat. Take a freshly laid ootheca from an African M. religiosa and put in Northern Europe at the same time the indigenous M. religiosa are laying their first oothecae. Take a freshly laid Northern European M. religiosa ootheca and place it in Africa. Then see what happens.

What does anyone here think would happen?

Scott

 

[Hypoponera]

I don't think your test would be much help. The northern ooth would not hatch, but the southern ooth in central europe would probably do just fine. With the possible exception of L. minor, no US mantid requires a diapause to survive winter. But Stegmomantis sp, Yersiniops sp, Tenodera sp, and Iris oritoria all do quite well. Yes, a few ooths are killed off by late frosts. But the species survive. I think the same would be true of the southern M. religiosa ooth placed in central Europe. But that's not to say your test isn't worth trying.

The test I would like to try is breeding specimens from both populations for a few generations. I am still a believer in the old definition of a species. If that cross produces viable offspring, then they are the same species. If the offspring are sterile, then they are two different, but very closely related species.

Looks like we will need a supply of Luke's M. religiosa to work with!

 

[sidewinder]

Hypoponera,

I think you are correct, the freshly laid Northern European Mantis religiosa ootheca would never hatch in Africa. I think the freshly laid ootheca from an African M. religiosa would hatch in northern Europe but it could be at the end of the season and all nymphs would die. I suspect the two populations bred together could produce viable offspring that could reproduce. That's why I would say that one population is a subspecies of the other. Similar to Canis lupus and C. l. familiaris.

You are right, I should not have used the word "require" in my diapause statement regarding species found in temperate regions. I should have used "support" instead. This means there must be some noticeable time delay in the start of the incubation process otherwise ootheca from temperate species that don't require the diapause would start the incubation process before the cold temperatures arrived. Or is there some other mechanism in play here that I am missing?

Scott

 

[Hypoponera]

There are many possible environmental conditions that may speed-up or delay hatching. Heat units are the one we usually think of. But some species may also respond to changes in photo period and/or humidity levels. Only some serious research would tell for sure. I don't think any research into diapause has actually been done.

Our native species have the ability to survive a normal winter just fine. So the onset of cold weather must delay hatching. But that cold exposure is not a requirement. S. limbata ooths usually take 8 weeks to hatch at 80F. So that produces a safety window to help the developing eggs. They have a good chance of not hatching until the risk of a late freeze has passed. I do not know the minimal time of development needed for M. religiosa. So it is possible that a southern ooth would survive in central Europe just as well.

 

[sidewinder]

Hypoponera,

My question would be can the incubation start and then be halted or does the incubation process need to start and finish after the cold season. In other words, can the young begin to develop in the egg and stop that process because of cold weather? Or, once the young start to develop, must that process finish?

Scott

 

[MantidLord]

So if one did adapt from another, which one adapted from which? In other words, where does the species originate? I know its common name is European mantis, but I just want to be sure since it's so widespread.

 

[Orin]

Did you guys read thisr. Yager is the Dr. David Yager that contributed to the book "The Praying Mantids". He knows what he is talking about. If he says there are M. religiosa in parts of the world that don't need a diapause, I would tend to believe him.

Scott

Southern Europe has seasons. If you had evidence that M. religiosa has multiple generations each year or other plausible explanation for a year-long growth cylce without diapause in those countries that would be a far different story. I imagine Dr. Yager's quote doesn't say what you think you're reading.

 

[sidewinder]

MantidLord,

It is important to note that basically all insects species trace their origin to the tropical equatorial zone. And, from what I have read, no successful insects in the tropical equatorial zone trace their roots to extratropical species. Based on that information, it would make sense that Mantis religiosa evolved in the tropics and spread to Europe from there. As the species moved farther north, it had to adapt to the temperate seasonal climate via obligatory diapause in the ootheca stage.

So I need to change which population I label as species and subspecies. Here is what I propose the new names should be:

Mantis religiosa

Mantis religiosa diapausa

Mantis religiosa diapausa would be the name for the European population.

Yes, we will see this tomorrow in all entomological text!!

Scott

 

[sidewinder]

Southern Europe has seasons. If you had evidence that M. religiosa has multiple generations each year or other plausible explanation for a year-long growth cylce without diapause in those countries that would be a far different story. I imagine Dr. Yager's quote doesn't say what you think you're reading.

Orin,

Why don't you tell us what you think Dr. Yager's quote does say. Here is the quote again:

"Because mantises are primarily tropical in distribution, the issue of diapause doesn't come up often. Even M. religiosa, which needs diapause over some of its range, does not in others (southern Europe, Africa)."

Let's assume for a moment that Dr. Yager made a mistake including southern Europe in his statement. What about Ghana in Africa? The only seasons there are "wet" and "dry" and both are hot. There is no way diapause could be broken in Ghana so the Mantis religiosa there would breed year round. Or do you have some explanation as to how this would not be the case?

Scott

 

[Hypoponera]

Hey Orin,

True, southern Europe does have seasons. But I don't remember many harsh winters when I lived in northern Italy. Likewise, Egypt does have a winter of sorts, but it wasn't harsh like Germany had. The winters in these southern locals would be cold enough to stop egg development until spring. So I believe 2 or more generations are not a needed requirement.

I think the quote was quite to the point. The southern poulation does not require a diapause. It still may only go through a single generation per year though. A second generation would require a location on or very near the equator. Does the species exist at such a location? If so, start looking for multiple generations. Then again, maybe keeping some of Luke's mantids at a steady 95F year round will produce multiple generations. So again, we need to work with some of Luke's stocks!

 

[sidewinder]

A second generation would require a location on or very near the equator.

According to page 283 of The Praying Mantids, the species Mantis religiosa is present in Ghana. Ghana is very near the equator. What could stop M. religiosa in Ghana from having overlapping generations and multiple generation per year?

Scott