Ooths outside hatch in fall in So. Cal?

[kamakiri]

I absolutely love the recent addition of so many brilliant, highly educated minds on this board. It makes for some very interesting, highly entertaining, if not somewhat pointless arguements. :lol: "Kicked to death by a canary" HA!!!! I love it.

You just made my day Phill!

+1

But I thought there was only *one* brilliant, highly educated mind added to the board lately ...and I certainly don't make the cut!

 

[PhilinYuma]

Pecca fortiter!

Have you more experienced members noted that sometimes our posts wander slightly off a thread's topic?

The question in this one was whether S. limbata nymphs hatched in October in Pasaden CA could survive the Pasadena winter. My guess is that they will not, due to the cold and lack of suitably sized prey.

Less obvious is the answer to the subsequent question about diapause in the ootheca of mantis species indigenous to the southwestern states, and I can claim, without fear of contradiction, that some of my responses comprised a clusterfunk (cute US military expression, "cockup" in the British Army) of factual and interpretive errors.

Firstly, contrary to what I said or implied, Pasadena, Yuma (indeed, all of Yuma County) and San Antonio all experience frost during the winter. My error partly arose from examining the nightly temperatures in December and January in these three cities without realizing that "frost can occur on grass and other exposed surface objects, while the temperature of the free air only a few feet above the ground is several degress higher than this critical temperature."

More importantly, I tacitly but wrongly implied that freezing was a prerequisite for diapause, while of course it is not. Ootheca stored in captivity and kept in the refrigerator for a period (any agreement on how long -- four- five weeks?) never experience an ambient temperature below freezing.

It seems to me that ootheca from locally caught, indigenous mantises are most easily and safely wintered outside, where it is not necessary to second guess how much humidity they need. Are many members doing this? I shall be doing this with my two S. limbata ooths, but if my female lays a third (go girl!) I shall winter it indoors, compare results and report them here in the spring.

 

[sidewinder]

PhilinYuma,

Actually, the original question involved some new spiderlings in his garden and whether or not they should have hatched this time of year and if that meant that the Stagmomantis limbata ootheca in the same garden would hatch early too.

Based on what I can recall of my 27 years living in Pasadena and the local area, there just aren't enough prey insects available to sustain a population of mantids during the winter. Even though the winters are mild, it seems most insects go into their typical winter mode, whatever that might be for each species. There are time periods where significant frost each morning is common. In other words, what you say about winter and food supplies in your last post are correct. If S. limbata hatched in October or November, they would not survive long.

But that still does answer the original questions.

Arkanis later told us he believed the spiderlings to be Green Lynx spiders. If they are Peucetia viridans, then it is normal for the spiderlings to hatch this time of year since they overwinters as early instar spiderlings. In other words, these spiderlings being present means nothing in regards to the S. limbata ootheca.

So we are left with these questions:

Because of the extended warm weather, is there a good chance that the S. limbata ootheca outside in the garden will hatch early and the first frost will kill the nymphs? Is this a cause for concern?

This is why the discussion correctly focused on diapause. As I said before I don't know what kind of diapause that S. limbata goes through.

I have been told that only one species of mantid in the U.S.A. goes through an obligate embryonic diapause (i.e. a required diapause) and that is Mantis religiosa. If S. limbata went through an obligate embryonic diapause, it wouldn't matter how long warm weather persisted after their oothecae were laid because a period of colder weather would be needed to break the diapause.

So let's assume S. limbata supports a facultative embryonic diapause. In other words, diapause is not required but entered if certain conditions present themselves. The two mechanisms that make the most sense for facultative embryonic diapause in S. limbata are photoperiod and temperature. Photoperiod is the most likely since higher temperatures persist long enough for the oothecae laid early in the season to incubate and hatch.

If we assume the facultative embryonic diapause for S. limbata is caused by photoperiod, there is no reason to worry that an S. limbata ootheca placed outside in the garden will hatch early so there is no cause for concern.

Having said all of that, it will be very interesting to hear what actually happens with the various oothecae that Arkanis and you incubate indoors and outdoors. We should soon know if the diapause for S. limbata is obligatory or facultative.

This thread stayed mostly on topic and has been quite interesting. I certainly have enjoyed it.

Scott

 

[darkspeed]

Going a little off topic is not really much concern to me... it happens to almost every thread. I just find it amusing that the smarter, more knowlegable or more educated the contributers are the more the disagreements seem to be about the smaller, less significant details, and sometimes it boils down to my _______ is bigger or better than yours. Again I am certainly not complaining, as I find it to be rather entertaining and quite interesting.

 

[kamakiri]

Well, the difficult part is that sometimes a whole point hinges on the details.

I've seen a LOT of assumptions about diapause and its requirements. But it think the typical opinions on the subject are a little too narrow.

Arguing gets tiresome...but I did want to make a point about the open hostility, which I think is not necessary

 

[sidewinder]

I've seen a LOT of assumptions about diapause and its requirements. But it think the typical opinions on the subject are a little too narrow.

Do you care to elaborate on this? What assumptions do you have a problem with? What opinions are too narrow?

Scott

 

[MantidLord]

Do you care to elaborate on this? What assumptions do you have a problem with? What opinions are too narrow?Scott

Oh my goodness just let it go.

 

[kamakiri]

Do you care to elaborate on this? What assumptions do you have a problem with? What opinions are too narrow?Scott

It's the general opinions of what I've read...here and otherwise in the scientific community. I think we have the tendency to oversimplify.

Regarding diapause trigger or requirements, it's the thinking that there's a finite temp or daylight threshold to begin or finish diapause. What if it's both? What if it's more of a range? What if it's just a delta of either or both? So many factors to consider beyond our expertise, in this forum and in the world.

If we look back in recent history, we can see how far along we are in the workings of biological mechanisms. It only makes me think of how little we actually know. Both you and I have been studying such subjects since the '70s...I thought it was all reasonable and factual back then...I think a lot of it has since proven to be false or only partly correct. That's one of the main things that makes me very skeptical of everything I read, even if it is current.

 

[PhilinYuma]

PhilinYuma,

Actually, the original question involved some new spiderlings in his garden and whether or not they should have hatched this time of year and if that meant that the Stagmomantis limbata ootheca in the same garden would hatch early too.

Ha Ha! You are quite right, of course Salomonis, the joke is on me!! When I read Arkanis's original post, it mentioned putting out the S.limbata ootheca and then seeing "spiderlings" emerging. The mention of the spider's species did not occur until the next post (if I remember correctly), and being very new to the hobby, I thought that this was some cute term for newly emerged mantis nymphs rapelling down their silken lines, analogous to fishy "fingerlings" or the mythical "cooties" that my captive population of Chicago area kids used to warn each other about. Too much psycholinguistics will rot your brain!!

Well, Arkanis, if Salomonis and I agree that, according to our limited data, the mantis nymphs are not likely to emerge until after they have been chilled, you have nothing to worry about. They simply wouldn't dare to emerge until after a chill. I have been concerned for those tiny critters since I read your post, particularly since they are the same sp. as my only adult mantises, so now I shall sleep better.

One of the infuriating things about the mantis ooth (another cute term!) is that however hard you stare at it, you cannot tell whether the eggs are in diapause, germinating, dead or infertile; it just stares blankly back ast you. The immature grasshoppers near my house go into diapause in the summer, when the grass tends to dry out and lacks the necessary nutrients for their development, but at least you can observe and time the phenomenon.

You often mention photoperiod as a possible mediator of diapause, Salomonis, and while I know that it is a common mechanism and much more reliable than temperature fluctuation, I can't dig up anything that posits this phenomenon in mantids. Do you have any articles, web pages or "personal correspondence" that throws any light [sad pun emoticon here] on this? My thought is that since a lot of people have successfully raised this species (S. limbata] indoors without regard to photoperiod, it is probably not a factor.

 

[sidewinder]

kamakiri,

As I said in my first post in this thread, clearly diapause in various mantid species is not well documented and, from what I can determine, not well studied.

There is a lengthy article discussing diapause in the Encyclopedia of Insects (Resh and Cardé, 2003) that is quite good.

In the article, the facultative pupal diapause of Sarcophaga bullata, the Flesh fly, is used as an example. It shows what percentage of S. bullata, kept at 25° C, entered pupal diapause at what photoperiod. When the photoperiod was longer than 14 hours, no S. bullata entered pupal diapause. But, when the photoperiod was 13.5 hours or less, about 85 percent of the S. bullata entered pupal diapause. Lower the temperature the S. bullata pupa are kept at to 18° C, and nearly 100 percent entered pupal diapause when the photoperiod was 13.5 hours or less. Temperature doesn't trigger the diapause, but lower temperatures do increase the likelihood of it being induced.

The embryonic diapause of Bombyx mori, the Silkworm, is discussed because it is the best understood. Bombyx mori uses a hormonal mechanism to enter diapause. Interestingly, the hormone is present in the embryos only if the mother's embryo was subject to an appropriately short photoperiod.

While the exact mechanisms at the molecular level are still unclear, the environmental cues are well understood. The knowledge of the hormonal signals fall somewhere in between.

Scott

 

[sidewinder]

You often mention photoperiod as a possible mediator of diapause, Salomonis, and while I know that it is a common mechanism and much more reliable than temperature fluctuation, I can't dig up anything that posits this phenomenon in mantids. Do you have any articles, web pages or "personal correspondence" that throws any light [sad pun emoticon here] on this? My thought is that since a lot of people have successfully raised this species (S. limbata] indoors without regard to photoperiod, it is probably not a factor.

PhilinYuma,

The reason I suspect photoperiod as what induces diapause in Stagmomantis limbata is that, in the southwest anyway, using temperature would be unreliable. Oothecae laid early in the season would be exposed to warm temperatures for a very long time. Temperature may play a part, but I don't see how it could be the primary motivator.

The photoperiod experienced by oothecae kept inside is dictated by the lights inside, not the day length outside.

Scott

 

[PhilinYuma]

PhilinYuma,

The photoperiod experienced by oothecae kept inside is dictated by the lights inside, not the day length outside.

Scott

My point exactly! Aside from the variable period spent in the refrigerator in almost constant darkness, some are kept in paper bags until spring, and some, no doubt, find a place in their owner's living area, which is likely to have a much longer photoperiod (and light of a substantially different wavelength), than they would have outside. In other words, almost no ootheca kept indoors is likely to experience anything like the photoperiod that obtains in nature, yet this does not appear to prevent them from hatching. On that basis, I think it unlikely that photoperiod can be significant. Your thoughts?

[happy emoticon here in reponse to an Email from a guy in Ohio saying that I can have a "praying mantis nest european" for $3.00]

 

[sidewinder]

PhilinYuma,

I'm confused. All I am saying is that a short enough photoperiod will induce a diapause and I don't think temperature could be the primary inducer since that would be so unreliable. The reason being how warm the temperatures can stay, in the southwest, well into October and even November. Basing diapause on day length would be ultra reliable since that is extremely consistent.

All it would take would be one extra long warm season in an area to kill out an entire species in the area if entering diapause were based on temperature alone. Using temperature to break diapause makes a lot of sense. But not as a reason to enter diapause in the south west United States.

Scott

 

[PhilinYuma]

PhilinYuma,

I'm confused. All I am saying is that a short enough photoperiod will induce a diapause and I don't think temperature could be the primary inducer since that would be so unreliable. The reason being how warm the temperatures can stay, in the southwest, well into October and even November. Basing diapause on day length would be ultra reliable since that is extremely consistent.

All it would take would be one extra long warm season in an area to kill out an entire species in the area if entering diapause were based on temperature alone. Using temperature to break diapause makes a lot of sense. But not as a reason to enter diapause in the south west United States.

Scott

Perhaps I wasn't clear. First let's look at whether temperature or photoperiod is the better strategy for ooth survival I agree completely that photoperiod is a constant and temperature can vary substantially from year to year, and if I were a pregnant mantis, I would definitely go for the former in order to give my babies the best possible chance in life (climate adaptation). I would also lay them in a secluded spot where birds couldn't find them and perhaps guard them from predatory and parasitic insects (predator-driven adaptation), but I am not.

When a genetic mutation takes place, it either kills the host, makes no difference, or gives the host a survival edge that causes it to succeed better than hosts of the unmutated gene in the following year. If that trend continues for enough years, it will be carried by more and more individuals. However, if the condition that it benifited from changes abruptly, like a substantial rise in the winter temperature, the population will be dramatically reduced in the following year, and if that trend continues it might die out altogether in that area. If this anomaly obtains over a limited area and the winter temperature then drops back to its original range, the area will be repopulated by surviving parapatric conspecifics, or, if an allopatric popluation, the area may become dominated by an endogenous competitor. If, however, the anomoly is sufficiently widespread and no mutation occurs that will cause adaptation to it, the species, like 99% of all other living creature over time, I understand, will become extinct. And that's the way it is. There is no "plan" or more reasonable strategy where there is no reason. Sadly, we can see environmental indications of such a warming trend already, and if the "six degrees" scenario becomes reality, it won't only be the mantids that disappear, stable photoperiod or not.

But neither your nor my amateur theorizing, though great fun, will make the slightest difference to what is actually happening. What we need is an Elegant Experiment.

[Hiatus, while the author meditates]

O.K. I dont have an elegant experiment, but I do have a rough and ready one. My second ooth has not yet been exposed to a period of cold or been taken outside to experience a shortening photoperiod, which will reach its minimum around December 22nd.

I shall leave the original ooth to weather outside with a normal photoperiod, and tomorrow, I shall replace my work lamp in the patio with a flood which will provide the second ooth with either natural or artificial light for 18 hours a day, or four more hours per day than in May, when most ooths should have hatched. The results will not "prove" anything, but a successful hatch will be consistent with the temperature theory and failure will be consistent with the photoperiod theory "all other factors being equal" (fat chance). I suspect that I shall be dead before I can generate a sufficiently large N to be statistically significant, but if a few more members of the board would like to spend some time and effort in duplicating or improving the experiment.... Any takers?

O.K. then, how about this? How many members have successfully hatched an ooth of this species that was kept indoors and recieved light beyond daylight hours? Was it refrigerated or not? An ooth that was maintained in an environment that recieved a consistent ammount of light and still hatched would tend to negate the photoperiod contention, but an otherwise unaccountable failure to hatch under these conditions would support it.

Is this fun or not!

 

[sidewinder]

PhilinYuma,

It will be interesting to see the results of your experiment. I look forward to hearing what happens with the Stagmomantis limbata ootheca that Arkanis has incubating inside as well.

As I said, I have suspicions but no facts when it comes to my ideas regarding diapause in S. limbata. The only data I have says that most incidences of facultative embryonic diapause in insects are induced by photoperiod. Add that to the sustained warm temperatures in S. limbata's range well after the oothecae are laid, and I feel pretty good about what I suppose. But, it the diapause could very well be brought on by colder temperatures. Or, it could be an obligate diapause. We'll no more soon I suspect.

Scott

 

[darkspeed]

My experience with ootheca is limited...of the ones I have had, the ones that did hatch did so without much help... that is, I put them in the same environmental conditions my mantids are kept in and they hatched just like that. They were all tropical species as well.... So my question is:

Is lower than optimum temps the only way to postpone hatching? How else would you keep a tropical ooth from hatching? Obviously they arent expecting a cold period, and I am afraid introducing one would be detrimental, but sometimes I would like to have a little more control over when they do hatch.

Secondly. You guys have frequently mentioned southwestern warmness, and there is no denying that is does stay warmer longer in the southwest. However, though I have not experienced it for myself, it is my understanding that nights in the desert can get brutally cold, and dip down as far as 40f even in non winter months. If my understanding is correct, then in an arid region like the southwest, wouldnt it be possible that an exceptionally cool september or october night followed by a reasonably warm day for that time of year could initiate a premature temp based diapause followed by a subsequently premature hatching?

 

[sidewinder]

DARKSPEED,

I don't have any experience trying to slow down the hatching of oothecae from tropical species so I can't tell if there are any side effects of using cooler temperatures to in an attempt to do so.

Deserts and high deserts get cold at night in the winter months, with high deserts getting much colder. During the summer months, it is not uncommon to have night time temperatures in the high 90°s F in the desert.

Pasadena in not either of those though. Here is the average low temperatures for Pasadena for the months that matter in regards to this situation:

March - 52° F

April - 54° F

May - 58° F

June - 61° F

July - 65° F

August - 66° F

September - 65° F

October - 60° F

Stagmomantis limbata start laying oothecae in late August and they hatch from early March to early May. A warm October could see a little more than two full months of warm temperatures at night for oothecae laid in late August. If photoperiod where not a factor, there is no reason not to believe that some oothecae would hatch before the cold set in.

Once diapause is entered, I am sure it takes a long period of cold temperatures to break the diapause. Probably in the range of several months of sub 60°. Then it would take periods of warm temperatures over 70° to cause the oothecae to hatch.

Again, I don't know for sure that S. limbata does not have an obligate embryonic diapause. If it does not, I do not know what induces the facultative embryonic diapause. But, considering the climate of the habitat of S. limbata, photoperiod makes the most the sense. That along with photoperiod being the most common inducer of facultative embryonic diapause in the insect world, makes me feel comfortable positing photoperiod as the inducer.

Maybe we will get some data in the next few weeks to months that will enlighten us on the subject.

Scott

 

[kamakiri]

As I said in my first post in this thread, clearly diapause in various mantid species is not well documented and, from what I can determine, not well studied.

I think we agree on that note. It is part of why I feel the discussion should not be so tightly defined.

Even some of the phrases we've used could be erroneous from the beginning. We can say things like, "enter diapause"...but my feeling is that it is possible for a temperate species to oviposit directly into a state of diapause. Changing that assumption could mean exiting diapause would only require a positive delta T. We should also not be looking too hard at the months or conditions where the ooths hatch...but perhaps a month or two before...when the ebryos start developing...or just finish developing.

Just more food for thought...

It would be nice if we had solid examples for mantids similar to your flesh fly example.

---------

Still trying to figure out what parameters I'm going to test with my religiosa ooths. My 7th was laid this morning.

 

[sidewinder]

kamakiri,

Well, maybe we should define some terms here so we are clear:

Obligate embryonic diapause: This form of diapause happens each generation and is not induced by environmental cues. The diapause is entered at some state in the development of the embryo. This could be at fertilization, when the first instar is just about to hatch, or somewhere in between. Typically, some period of chilling is required to break the diapause and temperature or photoperiod are the cues to start development again.

Facultative embryonic diapause: Environmental cues are used to determine whether or not to enter diapause. These cues include photoperiod and temperature. The diapause is entered at some state in the development of the embryo. Typically, some period of chilling is required to break the diapause and temperature or photoperiod are the cues to start development again.

In facultative embryonic diapause, there is a prediapause period. It is during this period that environmental cues are evaluated. I can find no reference to suggest that facultative embryonic diapause can be initiated by the mother. That would imply an obligate embryonic diapause since environmental factors present for the embryos would not factor into entering diapause.

In areas where photoperiod vary significantly, photoperiod is the normal impetus to enter facultative diapause since it is much more reliable than temperature as a cue. It is common for temperature to enhance the photoperiod response. Near the equator, where the photoperiod does not vary much, temperature is the normal impetus to enter facultative diapause.

From what I understand, most Mantis religiosa in the USA have an obligate embryonic diapause. But it is possible some groups in more southern areas support a facultative embryonic diapause. I don't know if that means Florida only or if that might include southern California and parts of Texas.

Scott

 

[PhilinYuma]

You guys have frequently mentioned southwestern warmness, and there is no denying that is does stay warmer longer in the southwest. However, though I have not experienced it for myself, it is my understanding that nights in the desert can get brutally cold, and dip down as far as 40f even in non winter months. If my understanding is correct, then in an arid region like the southwest, wouldnt it be possible that an exceptionally cool september or october night followed by a reasonably warm day for that time of year could initiate a premature temp based diapause followed by a subsequently premature hatching?

It doesn't seem likely, Darkspeed, since one cald night and one warm day don't seem to induce hatching. It's good to hear, though that someone beside me is interested in the fate of those poor little hatchlings. Nature ("whatever we understand it to be") seems to have much more leeway built into its mechanisms than we sometimes give it credit for. I don't think that an ooth laid in the beginninmg of October and then exposed to a very cold night and a hot day (and at least in this area, such a sequence of events would be very rare), would come to harm, but if it did, then the ooths laid in November by the same females would survive. A much more serious disaster would be something like a brush fire, again very unusual, but not impossible, in December. In that case, the whole generation, adults (soon to die anyway) ooths and all would be lost, and next year there would be no S. limbata in that area. Furthermore, the new growth vegetation may well be unsuitable for this insect, so it might not support a new population for years. But as soon as it became suitable, S. limbata would come flocking back (and I am talking about a parapatric population here), like Sooners when Oklahoma was opened up to settlers.

If the destroyed population was allopatric, though, like some (imaginary) island in the middle of the Colorado River, it is just as likely that the ecological niche once occupied by our favorite mantis would be taken over by another species altogether. We sometimes hear that "Nature doesn't care about the individual, only the species." What nonsense! Nature (or nature) doesn't care, period! I have been harping on this nihilistic view of nature for a few posts now I realize, but I don't know of any other view (Intelligent Design, anyone? LOL!) that fits the facts.

Sunny, peering over my shoulder, like a vengeful troll, made two comments. "Don't you worry about insulting the believers in ID?" [No] and "You used 'sympatric' when you should have said 'parapatric', and if you don't know what the words mean, why should anyone else?" Well I corrected the error, and the answer is that I am lazy and sometimes use a technical word to avoid explaining what it means. For anyone who might not have met the patric family and doesn't find this post exciting enough to bother Googling them, when considering different populations of the same species (in this case), a population cut off from its fellows, like Brazil_Fisherman's Taiwan popluation, is alloptric; two or more populations that are contiguous are parapatric, and two or more different species sharing the same area are sympatric.

Time to take my dog for a walk and a certain smart assed kid home.