# mortality rates?



## desana (Sep 28, 2008)

can anyone post a list of mantids that seem to have the highest mortality rates as nymphs pls. the only ones i know of are chinese &amp; european... cheers.......ive tried a seach but cant find anything .........


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## Rick (Sep 28, 2008)

I doubt you will find much info on that subject. You may get some peoples personal experiences though. The mortality rates would depend on many factors. In general many mantid species lay a large amount of eggs to help ensure at least a few will make it due to the high mortality rate of nymphs.


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## Christian (Sep 28, 2008)

The mortality rate isn't a feature of certain species but of certain breeders...


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## sidewinder (Sep 28, 2008)

Christian said:


> The mortality rate isn't a feature of certain species but of certain breeders...


Christian,

It's a given that the conditions in which nymphs are raised will affect mortality rates. But that is not the question being asked.

You can't tell us that every mantid species has the same nymph mortality rate. Unless, of course, mantids are unique in the animal kingdom. So your glib answer doesn't really help anyone and is technically inaccurate.

Scott


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## Christian (Sep 28, 2008)

Calm down. As with "inbreeding", mortality rate is overestimated in mantids. It happens because of inaccurate conditions. In nature, mantids die because of starvation or predation. In some regions, unusual climatic factors may add (late frosts, early or severe dry season etc.). They do not die without any reason or to fit a statistic. Starvation and predation can be controlled in captivity. Remains the climatic reason. One might think this can be sorted out in captivity as well, nevertheless many people fail in assuring the right conditions.

As a consequence, mortality rate is usually caused by the breeder. No animal dies instantly without any reason. Genetic factors account for only a minority of losses.

Is this more accurate to you?


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## sidewinder (Sep 28, 2008)

Christian,

Calm down? I am certainly calm. Just because someone points out a glib response from you does not mean you need to tell them to calm down.

In captivity, animals of all types die for unknown reasons. A lot of research goes into this phenomenon so clearly there are not a lot of concrete answers. There is also a lot research into the variability of the survival rate amongst species in the same genus in captivity.

So, if we had all the knowledge regarding environmental and nutritional factors that effect premature death of any animal in captivity, we could eliminate those causes. However, some species die more often than others even when you remove starvation, predation, and climatic factors. And that leaves us with the original question, doesn't it?

Scott


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## Christian (Sep 28, 2008)

sidewinder said:


> However, some species die more often than others even when you remove starvation, predation, and climatic factors. And that leaves us with the original question, doesn't it?


No they don't. No animal dies for "unknown" reasons. They may just be just unknown to us. This doesn't mean the mortality rate is unusually high. The difference between the mortality rates of the same species at different breeders is due to better or worse adjusted conditions. People should learn to take responsibility for their animals and their abilities and not state all the time that all failures are the fault of the animal: inbreeding, high mortality rates, all these are just myths.


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## sidewinder (Sep 28, 2008)

Christian said:


> No they don't. No animal dies for "unknown" reasons. They may just be just unknown to us.


Christian,

Sure they do. "Unknown to us" is the same thing as "unknown". Animals don't die for no reason. Since we don't know everything about every species, animals die for unknown reasons and, in captivity, mortality rates differ from species to species. Which gets us back to the original question.

Scott


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## etb99 (Sep 28, 2008)

Christian makes a lot more sense than you do Scott and I don't mean that in an unkind way.

In general the number of offspring any animal produces is related to the survival rate of that offspring, due to factors in the environment, not some innate mortality rate. If mantis A produces 200 nymphs and mantis B 40 then that is because A is preyed upon more, food is more difficult to find, climatic factors are more variable etc., not because A is more likely to keel over suddenly for no reason.

If there are significant differences in mortality that is more than likely due to the fact that we don't provide the right conditions, i.e the breeder like Christian said.

IF we knew the perfect conditions for each species I'd bet we would always raise a similar % to adulthood, lets say 95% of each species. If you believe that is not true I'd love to see some data on that.


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## sidewinder (Sep 28, 2008)

etb99 said:


> Christian makes a lot more sense than you do Scott and I don't mean that in an unkind way.In general the number of offspring any animal produces is related to the survival rate of that offspring, due to factors in the environment, not some innate mortality rate. If mantis A produces 200 nymphs and mantis B 40 then that is because A is preyed upon more, food is more difficult to find, climatic factors are more variable etc., not because A is more likely to keel over suddenly for no reason.
> 
> IF we knew the perfect conditions for each species I'd bet we would always raise a similar % to adulthood, lets say 95% of each species. If you believe that is not true I'd love to see some data on that.


etb99,

You are making my point for me. Christian's answer is fine from a theoretical standpoint. The problem is that we don't know the perfect conditions for each species so there is no way to eliminate the unknowns which will result in variable mortality rate amongst species raised in captivity.

Christian is correct to point out that breeder error causes a lot of mortality. But that does not mean that all variability in mortality rates is due to breeder error. Some of this variability is due to a general lack of knowledge of the needs of certain species. As we become more knowledgeable about the needs of these species, their mortality rates will go down.

Scott


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## OGIGA (Sep 28, 2008)

Oh goodness... this question is never going to get answered, is it?

Anyway, I found that stagmomatis has a pretty high mortality rate. And for those who disagree and think it's because of me, well maybe it is.


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## Christian (Sep 29, 2008)

In general, temperate zone species do worse in captvity than tropical ones. Possible exceptions don't break the rule.



> But that does not mean that all variability in mortality rates is due to breeder error. Some of this variability is due to a general lack of knowledge of the needs of certain species.


Not knowing the conditions falls into the "breeder error" category, as the fault is to be found at him/her, irrespective of being intentional or not. Not knowing better doesn't mean we have to blaim the mantids. I wanted to point out that there is no such thing as a high innate mortality rate in any species (with the exception of some parthenogenetic strains). It is not innate, it is caused by the environment, and as such falls under the responsibility of the breeder. That's the difference.


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## sidewinder (Sep 29, 2008)

Christian,

By definition, the only way a person can error is if an action is known to be a mistake. Let's posit for a moment that Drosophila melanogaster are slightly toxic to Parashendale Affinnis, but no one actually knows this. A breeder feeding Drosophila melanogaster to Parashendale Affinnis is not making an error. Drosophila melanogaster is an accepted food used by most all breeders to feed mantid nymphs. The error is in the knowledge or the lack of it. Not in the action.

I don't recall anyone suggesting that any mantis species had "high innate mortality rates". Nor do recall anyone blaming the mantids for dying prematurely. But, there is variable mortality rate amongst mantid species raised in captivity. I can say this without having specific knowledge because it is true for every genus. Why would mantids be any different?

Yes, breeder error is likely to blame for deaths some breeders attribute to the mantids. But, that doesn't change the fact that there is variable mortality rate amongst mantid species raised in captivity. Much of this variability is likely due to the lack of knowledge regarding the needs of the various mantid species. However, that does not change the validity of the question that desana asked.

S-


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## etb99 (Sep 29, 2008)

sidewinder said:


> Yes, breeder error is likely to blame for deaths some breeders attribute to the mantids. But, that doesn't change the fact that there is variable mortality rate amongst mantid species raised in captivity. Much of this variability is likely due to the lack of knowledge regarding the needs of the various mantid species. However, that does not change the validity of the question that desana asked.S-


What this shows it how important it is to ask the RIGHT question and how you ask it.

You words:

However, some species die more often than others even when you remove starvation, predation, and climatic factors. And that leaves us with the original question, doesn't it?

As Christian rightly answers you yourself suggest an INNATE mortality. Because if we remove all detrimental factors we should get close to 100% survival. To say that a mistake is only a mistake if you know you make it is semantics. WE kill mantids because we don't (always) know the perfect conditions.

We can argue this time and again, but hat seems pointless. Desana should have asked which species seem to be the most difficult to raise from birth in captivity or something like that. As it is the question has too many variables for any useful answer.


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## sidewinder (Sep 29, 2008)

etb99 said:


> Desana should have asked which species seem to be the most difficult to raise from birth in captivity or something like that. As it is the question has too many variables for any useful answer.


etb99,

That is the question, worded differently, that desana asked. Here it is again:

"can anyone post a list of mantids that seem to have the highest mortality rates as nymphs..."

Please note the "seem to have".

A certain someone decided to over complicate the question and make an indictment against breeders instead.

S-


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## desana (Sep 29, 2008)

sidewinder said:


> etb99,That is the question, worded differently, that desana asked. Here it is again:
> 
> "can anyone post a list of mantids that seem to have the highest mortality rates as nymphs..."
> 
> ...


i think i shouldnt have asked the question in the first place sorry for all the hassle its caused i meant in general by reading certain ppls posts in the past it seems that some seem to have higher mortality rates up to their second moult and just seem to die whether their are other factors involved with how one keeps the nymphs or whether its part of that certain species of mantids genetics i dont know but ppl have said certain species like europeans or chinese seem to have high death rates during their first couple of days of life. once again sorry for causing the uproar......


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## sidewinder (Sep 29, 2008)

desana,

You should not be sorry for asking a reasonable question. I too would like to hear people's opinion on which mantids are most difficult, for whatever reason, to keep alive from L1 to adulthood.

I apologize for participating in the hijacking of your thread but it bothers me when people with knowledge get overly technical when it is not necessary.

Now let's just hope some people chime in with their thoughts on which mantids are most difficult, for whatever reason, to keep alive from L1 to adulthood.

S-


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## Headspace (Sep 29, 2008)

People are discussing two seperate subjects here.

1. Mortality rates of the insect when it is out in the wild, doing its thing, in its natural habitat.

2. Difficulty of raising it (for whatever reason, such as difficulty mimicing its natural habitat in a closed environment).

The first one is easier to know than the second. The second is never going to be fully proven for every species since every single hobbyist out there is going to tell a different story. Second, and this is coming from my other hobby more so than anything else (my nickname should provide a hint), but people never like broadcasting their mistakes. If you screw up and lose a whole batch of insects, it can be embarassing.

Personally Tenodera are all I've ever raised, and they tend to be problematic for me as nymphs. I lose nearly half, every time I do it. Right now I've got eight all on their 5th instar. The biggest problem has been from them getting killed during their molt.


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## desana (Sep 29, 2008)

sidewinder said:


> desana,You should not be sorry for asking a reasonable question. I too would like to hear people's opinion on which mantids are most difficult, for whatever reason, to keep alive from L1 to adulthood.
> 
> I apologize for participating in the hijacking of your thread but it bothers me when people with knowledge get overly technical when it is not necessary.
> 
> ...


dont apologies feel free to hijack. after all thats what these forums are for are they not.plps views and help. but i myself dont like it when you ask a simple question and i apologies for anyone that takes this the wrong way theres no need to get too technical cos it ends up causing all sorts of problems. ive only been around mantids myself for a couple of years before that i had spiders and scorpions but mantids for me are just fantastic im not knocking spiders and scorps by any means but for me if ya wanna see your pet sometime during daylight hours (unless you are nocturnal) then its no point having nocturnal pets. thats just my view. although i still like other inverts as far as the missus is concerned anything that has fangs , can sting and produce venom it dosnt get over the front doorstep (unless its the mother inlaw LOL! . o dear hope i havnt started another war by saying that LOL!.


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## Christian (Sep 29, 2008)

> A certain someone decided to over complicate the question and make an indictment against breeders instead.


I answered desana's question more properly than you did. I am not willing to attend a discussion which is artificially continued just for the sake of argumenting against someone - without even being willing to reflect over the arguments of the other side. You have really hijacked desana's thread, as your arguments fit neither my stuff nor the initial question. Desana asked for something like an innate mortality rate. I have pointed out that this doesn't exist. Take it or leave it, I have better things to do than feeding a dead discussion. I have said everything "technically" important, there is nothing to add.


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## sidewinder (Sep 29, 2008)

Christian,

Here is my finally reply to you:

I never attempted to answer desana's question. For all practical purposes, neither did you. You took the academic approach which gave desana no practical information.

If mantid breeders do everything that is correct based on the current level of knowledge of the various mantid species raised in captivity, there still is a variable mortality rate. Why? Because we don't have the knowledge to do better. Yes, in a perfect world, the mantid mortality rate would generally be similar from species to species. But, we don't live in a perfect world and we don't know everything there is to know about the requirements of mantids raised in captivity. As new information becomes available on specific species requirements, mortality rates will go down.

In the mean time, there is data available that shows that some species are harder to raise to maturity than others. Even if the breeder does what is known to be correct. That is the information that desana was looking for.

S-


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## Rob Byatt (Sep 30, 2008)

I feel a little input from somone else is needed here  



sidewinder said:


> I never attempted to answer desana's question. For all practical purposes, neither did you. You took the academic approach which gave desana no practical information.


I'm sure Christian did give, in your words, practical information:



Christian said:


> Desana asked for something like an innate mortality rate. I have pointed out that this doesn't exist.


Sidewinder (Scott ?), I have one question for you and I don't mean this is a personal dig or a way to cause more arguments, but what exactly is your experience with keeping mantids - years, weeks, months ?


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## sidewinder (Sep 30, 2008)

Rob Byatt,

This is my last post in this thread.

The amount of experience I have raising mantids is not at issue here because I never tried to answer the valid question that desana asked. Christian's response was that any difference in mortality rate between mantid species is the fault of the breeder. After further discussion, it became clear that the only way mortality rates would be near equal is if breeders knew all about the special requirements of each species raised in captivity and continually maintained those requirements. That is academically or theoretically correct. But, in practice, not realistic. That's why there is variability in mortality rates amongst mantid species even when the breeders do nothing wrong based on current knowledge.

Now, we can discuss the fact that most breeders, even the best, are not perfect. Even if they know the ideal conditions for raising the mantids, the conditions will vary to some degree. The mantid species that are less affected by changes in conditions will have a lower mortality rate. Some species, for whatever reason, are just plain easier to raise than others. Just reading this forum and other forums that discuss mantid breeding makes that obvious. And not all of it because of bad breeders.

The bottom line here is that you have to look at the original question from a practical perspective and not from an academic perspective. Because that is how it was asked.

S-

P.S. In high school I raised a variety of insects, including mantids, for several years. My plan was to go into entomology or herpetology in college. While in high school, I worked two summers in the entomology department at Cal Tech (genetic research). I ended up in computer science instead because I thought there were more opportunities to make money there. I was right. In other words, I am not an idiot.


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## Rob Byatt (Sep 30, 2008)

I think you missed my point  

Experience has everything to do with answering this question.



sidewinder said:


> P.S. In high school I raised a variety of insects, including mantids, for several years. My plan was to go into entomology or herpetology in college. While in high school, I worked two summers in the entomology department at Cal Tech (genetic research). I ended up in computer science instead because I thought there were more opportunities to make money there. I was right. In other words, I am not an idiot.


Not sure of the relevance of the above, but you are right, this is a hobby, not a business. Come into it from a money standpoint and you are destined to fail.


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