Breeding Latrodectus

pannaking22

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I've been hunting down info on breeding Latrodectus and was curious to what experiences those of you on here have had? I went through these two threads

http://arachnoboards.com/ab/showthread.php?109658-Anyone-breeding-white-widows&highlight=latrodectus+breeding

http://arachnoboards.com/ab/showthread.php?78758-Latrodectus-breeding-advice&highlight=latrodectus+breeding

and learned a lot, but was more curious of a few of the simpler aspects to start off. Is there a recommended way to introduce the male to the female, or is it as simple as stick him in there and he does his thing? I know that if the male announces himself improperly there's a decent chance he could end up a meal and seeing as how I only have one male of one of my species, I'd like to keep him intact if possible. The females of some species seem more aggressive than others (L. hasselti sound fairly aggressive, especially considering that they eat the males >90% of the time), whereas other species seem much more laid back about the process. Of course there's some variation within a species, but that's another thread for another day.

I have a mixture of tropical, pan-tropical, and temperate species right now, and I was wondering if anyone exposed the more temperate species to cool temps for extended periods of time before attempting to breed them or to get a female to drop a sac. I know in the threads copied above, Buthus talked extensively on how he had to expose certain species (L variolus for example) to cooler temps for a few months to simulate winter conditions in order to get them to breed and thrive. I do also have L. pallidus, but my slings are very small now so I'm not worrying about breeding until I can at least sex them. Do these more temperate species need a cool down period every year, or is it more just to get them to breed? Some species seem to grow larger when they have a cool down period, but that's not something I'm looking to try right now.

Has anyone had issues with regards to temps, or is this mostly speculation at this point?

Also, many Latrodectus seem to do best in a dry(ish) environment, excluding tropical species such as L. bishopi, though the threads above mentioned keeping them at fairly high humidity (70-75%). I've noticed that mold growing on prey remains or the skewer pieces I put in for them to build their webs on doesn't really affect them, but I was curious to other people's thoughts/experiences with that as well.

I know that in the end, I could just ask the people that have sold/traded me some widows in the past, but I figure this thread could really serve as a good pool of information for anyone else who's interested in the future, not just on breeding, but maybe a bit on care as well ;)
 

Widowman10

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There's a section on my site about breeding, cruise through that if you'd like.

I've introduced males several ways, and they were almost all positive. The female seems to know pretty quick that it's a male, and the male can sense the pheromones on her web, so he knows what's going on too. L. hasselti females aren't really more aggressive than others, and it's slightly misleading to say they "eat the males." Rather, the males "offer" themselves to the females to be consumed. It's a very interesting reproductive strategy. I've had luck not varying temps from different species to drop sacs, many from different climates. Who knows if I would have had even more "luck" had I done that? My room did fluctuate in temperature with the seasons though, so that helped I'm sure. I live in Colorado (where it's very dry) and they have thrived for me. I do mist the web every few days or weeks so that they can get moisture though. You can tell when a widow needs moisture and when it doesn't. It's not a science, more of an art ;)

Are you working with any other exotics besides pallidus right now?
 

The Snark

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The museum in Darwin did several studies on Hasselti. The environment in the surrounding area is very hostile and the females tend to be voracious, killing anything entering their webs. It was found that well fed females exhibit a markedly lower inclination to attacking the males.
Also, in that area, temperature had no effect on reproduction as the variations from season to season were very minimal. Always > 80 F during the day, year round.
 

pannaking22

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As an update, one of my WC L. variolus females dropped a sac last night :)

There's a section on my site about breeding, cruise through that if you'd like.

I've introduced males several ways, and they were almost all positive. The female seems to know pretty quick that it's a male, and the male can sense the pheromones on her web, so he knows what's going on too. L. hasselti females aren't really more aggressive than others, and it's slightly misleading to say they "eat the males." Rather, the males "offer" themselves to the females to be consumed. It's a very interesting reproductive strategy. I've had luck not varying temps from different species to drop sacs, many from different climates. Who knows if I would have had even more "luck" had I done that? My room did fluctuate in temperature with the seasons though, so that helped I'm sure. I live in Colorado (where it's very dry) and they have thrived for me. I do mist the web every few days or weeks so that they can get moisture though. You can tell when a widow needs moisture and when it doesn't. It's not a science, more of an art ;)

Are you working with any other exotics besides pallidus right now?
Been through your site multiple times, Widowman. Absolutely love it :D Forgot about the sections eggsacs and things though (distraction with my thesis I'm thinking lol). I definitely wrote that wrong earlier saying the males get eaten, so thanks for the correction! It's good to know that temps aren't as big a a factor as I originally thought. I have a bit more humidity in central Illinois during the summer, but things dry out once winter rolls around. I've been able to tell pretty easily when some of my older widows get a little dry, but haven't really had that experience with the slings yet (perhaps because the ambient humidity is higher here?).

My other exotic species are L. curacaviensis, L. tredecimguttatus and L. sp. Mexico. Hoping to pick up a couple more exotic species in the future though as they become available. Worth noting that I'd be willing to trade some of my new sparassid slings for widows... ;)

The museum in Darwin did several studies on Hasselti. The environment in the surrounding area is very hostile and the females tend to be voracious, killing anything entering their webs. It was found that well fed females exhibit a markedly lower inclination to attacking the males.
Also, in that area, temperature had no effect on reproduction as the variations from season to season were very minimal. Always > 80 F during the day, year round.
Awesome stuff, Snark! Makes sense that a well fed female would be more likely to let the male live.
 

The Snark

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Interesting:
"In the case of redback spiders, the value of multiple mating for males may be low owing to an intrinsic constraint—redback males are functionally sterile after their first mating. (Andrade and Banta, 2002)"
 

Widowman10

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Interesting:
"In the case of redback spiders, the value of multiple mating for males may be low owing to an intrinsic constraint—redback males are functionally sterile after their first mating. (Andrade and Banta, 2002)"
Interesting indeed. But I believe this is the case (the majority of time) with many of the other species of male Latrodectus as well. The coil (sperm delivery mechanism) will break off inside the female, creating a blockage so that other males cannot mate with her. This of course renders the male effectively sterile. At least he has 2, haha! And I remember reading of a female that had 3 inside of her, so it doesn't guarantee 100% blockage evidently.
 

The Snark

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Interesting indeed. But I believe this is the case (the majority of time) with many of the other species of male Latrodectus as well. The coil (sperm delivery mechanism) will break off inside the female, creating a blockage so that other males cannot mate with her. This of course renders the male effectively sterile. At least he has 2, haha! And I remember reading of a female that had 3 inside of her, so it doesn't guarantee 100% blockage evidently.
Okay, I'm calling you out. Well, calling on you, your expertise and knowledge. Looking at the bigger picture, the evolution that has taken place to bring about these 'checks and balances' so to speak, and these checks being defeated at the same time, would you care to conjecture what exactly is going on?
Why is single male mating biologically preferred in these animals, and why is it also less than 100% effective? Expound? Postulate?

Is effective mating so common that the small chance that multiple matings is a significant factor, or so rare that the odds of effective multiple matings are so small as to not be a relevant factor?

I'm looking at this from a back seat very objective viewpoint. Hasselti is a very successful species in an environment so hostile it makes the southern California deserts resemble gardens of eden. Something underlying is going on here. Or, perhaps, the environs as the Kakadu, the extensive arid areas of the northern territory, are not, to this spider, anywhere near as hostile as is assumed?* Most certainly, prey for the Latrodectus in the Australian outback is exponentially more abundant than in southern California where Hesperus is equally well established.

* I spent a month hole poking in the area around Darwin and was surprised. The abundance of Hasselti was identical to what I observed of Hesperus in the dry riverbeds of the San Gabriel mountains of So. Cal. Millions of years removed from each other, yet environmentally adapted to have very similar population densities. Prey availability factors into this. In the environs around Darwin and throughout Queensland, there are various estimates of flying insects per cubic meter of airspace over an averaged 24 hour period. They ranged from ~<2 in the extreme arid areas of Arnhemland to 120 in the swampy areas near Jabiru. Millions of times more abundant that So. Cal. (Imagine sharing your personal space with 120 flying insects at any given time. The boat tour I took was an unreal nightmare)
 
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pannaking22

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Okay, I'm calling you out. Well, calling on you, your expertise and knowledge. Looking at the bigger picture, the evolution that has taken place to bring about these 'checks and balances' so to speak, and these checks being defeated at the same time, would you care to conjecture what exactly is going on?
Why is single male mating biologically preferred in these animals, and why is it also less than 100% effective? Expound? Postulate?

Is effective mating so common that the small chance that multiple matings is a significant factor, or so rare that the odds of effective multiple matings are so small as to not be a relevant factor?

I'm looking at this from a back seat very objective viewpoint. Hasselti is a very successful species in an environment so hostile it makes the southern California deserts resemble gardens of eden. Something underlying is going on here. Or, perhaps, the environs as the Kakadu, the extensive arid areas of the northern territory, are not, to this spider, anywhere near as hostile as is assumed?* Most certainly, prey for the Latrodectus in the Australian outback is exponentially more abundant than in southern California where Hesperus is equally well established.

* I spent a month hole poking in the area around Darwin and was surprised. The abundance of Hasselti was identical to what I observed of Hesperus in the dry riverbeds of the San Gabriel mountains of So. Cal. Millions of years removed from each other, yet environmentally adapted to have very similar population densities. Prey availability factors into this. In the environs around Darwin and throughout Queensland, there are various estimates of flying insects per cubic meter of airspace over an averaged 24 hour period. They ranged from ~<2 in the extreme arid areas of Arnhemland to 120 in the swampy areas near Jabiru. Millions of times more abundant that So. Cal. (Imagine sharing your personal space with 120 flying insects at any given time. The boat tour I took was an unreal nightmare)
These single matings may end up being the supposed ability for the strongest male to pass on his genes to the next generation. Weaker males may end up having to share eggs from the female because another male is also able to mate with the female (hence the female that 3 coils inside her). This could be due to anything from the weaker male not producing as much sperm or having smaller coils to that male being not quite as good at the whole spider sex thing. The second male that came along also could be a stud and is able to force his coil in among the others, despite not having as much space. I would be curious to see the genetic results of the offspring to see which ones got more genes from which father.

I also wonder if shape of epigynum could influence these matings? While each species obviously has a unique epigynum structure, there is potential for some small variation within a species, correct? Could allowing for multiple matings on rare occasions help widen the gene pool by allowing a male that also potentially has slight variation in his coils to mate with a mated female? I know there is plenty of ballooning going on, so that helps increase genetic diversity, but I'm just sort of taking a shot in the dark here that there could be other ways to increase it as well :D

Despite the hyperabundance of hasselti you were seeing Snark, I feel that I'm leaning towards extra matings for and by males to be pretty rare, especially in the more arid regions of Australia. This is pure conjecture since I've never been there (would love to visit someday though!), but obtaining necessary nutrients for growth and development seems like it would be a challenge. Males have to wander about to find females and I'm betting these males would also be seen as a juicy little bag of protein for most other predators in that area, be it other arthropod up to small birds and mammals. Out of all the males that reach maturity, how many are able to wander off and successfully locate a willing female? One must wonder what happened to that male that got the third coil in the female. Did he present himself as a meal and the female took him, or did he do his business and try to wander off to find another female?

Out of curiosity, if a male attempts to court an already mated female, does she make a meal of him, or just ignore him?

More thoughts on this to come later after I ID some ticks from Kenya and ponder the evolution of hasselti life and mating. Fascinating stuff guys!
 

Widowman10

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Sorry for the late reply, just saw your post. Pannaking had some good thoughts. Something I was thinking about while reading your response was that in female Latros, only 1 mating is really ever needed for sling production as the female is able to store sperm from the initial mating for very long periods of time. I've read reports of females whose egg count dropped dramatically after 15 or so eggsacs, but a subsequent re-mating (with a new male of course) boosted the egg count up significantly in the following eggsacs! So hopefully that answers your question a little Pannaking. Even in the case of the female with 3 coils, she must have accepted that male without making a meal of him right away.

I like the 'checks and balances' idea. But what's the number rule in biology: "there's an exception to every rule!" I guess there's some wiggle room in the checks and balances for a strong male to be able to pass along his genes (to be the third wheel, I mean coil). Or for the female to pass along her genes in the rare case that the original male whom she mated with was somehow sterile? Allowing a stud to come along and get things rolling again would be helpful I'm thinking. But that begs the question of why the capability is there in the first place? Perhaps so that the strongest/fastest and quickest male to reach the female gets the right to pass along his genes (provided he plays his cards right and does not get eaten). I can easily see how this trait would be extremely beneficial, especially since the "juicy little bags of protein" are out wandering around; selection would then favor those males who could reach the female first. This is fun, what are your thoughts on the above theory (about selection favoring the quickest male) Snark?
 

The Snark

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Just venturing an unscientific wild guess, it appears that nature will always try to side with a dominant alpha male. The coil blocking up the works then being a product of an unusual circumstance of an extended period of time in the evolutionary time line where effective mating was rampant and weaker genes were getting into the species.
That speculation is pretty weird. What mechanics that were involved and how the problem was detected and corrected offers the intelligent design folks some excuse for their misguided dogma. It is a pretty sophisticated alteration of the mating ability considering the changes had to take place over thousands, more likely a few million years.

Consider. Theory: The alpha had a lot of competition. The female altered to exclude weaker matings. (I just discovered I brought in a spider from the porch who is gleefully running all over my foot as I type). The alteration not only excluded weaker matings by the more vigilant and increased hostility of the female, but also left a window of opportunity open for multiple matings, ostensibly from supreme alphas. And while that was going on the females anatomy removed each partner from the gene pool. Survival of the species highly refined.
 
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Widowman10

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Just venturing an unscientific wild guess, it appears that nature will always try to side with a dominant alpha male.
Again, there are always exceptions! Here's a particularly fascinating one!!
http://evolution.berkeley.edu/evolibrary/article/sneakermales_01

It is a pretty sophisticated alteration of the mating ability considering the changes had to take place over thousands, more likely a few million years.
I wish I were more familiar with close relatives of Latros (Steatodas, but I imagine they might be similar? or Theriids in general?) to know how mating occurs in those groups.
 

The Snark

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Yes, absolutely. The random element. It isn't just an incidental but an intrinsic part of the evolution of all life. That which firmly negates intelligent design as nature constantly experiments, creating new species, genera, even families.

I have this feeling Steatoda is an interloper. A more recent evolutionary development that isn't as 'locked in' as the latro and may very well displace latro throughout the world eventually.
 

pannaking22

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You beat me to the sneaker males, Widowman! ;) Always fun to talk about (especially with regards to dung beetles!). There is always going to be a check in that regards, otherwise the genetic pool becomes a puddle and from the sounds of things, CB widows don't do particularly well once they interbreed for a generation or two. The big biology question of "which strategy is better?" then pops up. Is it better for males to mature faster and be more virile, but be smaller and weaker, or be the stud that takes longer to mature, but isn't as virile? The blending of the two means that everyone's genes have a chance, but I'd be curious to see population structures in areas where one side or the other is more dominant and observe it over time.

Another thought occurred to me after I had finished responding earlier, but I wanted to let it percolate for a couple days first. With studly males running rampant across the landscape and females being able to drop sacs until they die, what sort of influence would parasitic wasps/flies have? Not just those that parasitize the spiders themselves, but also the ones that parasitize sacs. I wonder if the areas with dense populations of hasselti in Australia are in areas where these parasitoids aren't able to survive as easily due to an inhospitable landscape? I know I'm derailing the thread a bit, but it's my thread so I can do that right? :D
 

Widowman10

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Good question. I would imagine that where there is an abundance of hosts, there would be an abundance of parasitoids. Flies and wasps can survive in some pretty extreme environments as well. I've seen some areas of Utah that are packed with widows as well (rivaling the density of hasselti in Oz?).

There have been documented cases of Philolema latrodecti emerging from hasselti eggsacs in Queensland.
 

pannaking22

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No surprise that the specialists would be willing and able to take a bit more abuse from the environment to stick with their preferred hosts, but more generalistic species may not be able to follow the hasselti into some of the harsher landscapes, which might lead to an abundance of widows (perhaps the same as what you saw in Utah and what Snark saw in California). Latitude and altitude may also have an affect. While these examples are both in completely different systems, birds in Hawaii are susceptible to avian malaria. Birds that survived were typically at higher altitudes than the vector mosquitoes and the pathogens could withstand. The same can be said of Chagas disease in the US. You can certainly find kissing bugs (Reduviidae: Triatominae) in Illinois and further north, but Chagas isn't an issue, with tested bugs coming up negative. Further south, kissing bugs can be infected with Chagas fairly commonly. There's just something about the climate that the pathogen can't survive. Could a change in climate that is advantageous for the widows be a massive disadvantage for many parasitoid species? So many deep ecological questions, I love it :)

I also wonder if these areas are so thick with widows that competitive species, such as Steatoda, can't quite get a foothold? I'd like to hear Smokehound's thoughts on the matter since he's seen areas where hesperus were quite common overrun with geometricus. I believe he's also had some success removing the geometricus and reintroducing hesperus. I know it's not Steatoda, but it's another theridiid with similar habits and habitats.
 

The Snark

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Since we are confusing ourselves anyway, allow me to toss a few more unassigned variables into the works.

I never gave much thought to parasitoids having an extreme overall effect of spider populations until I came here. At any given time I could check out our own house and the surrounding few acres and find several dozen mud wasp incubators with at least one spider victim in each. That the wandering/hunting spiders survive here at all is pretty amazing. Mostly like only their nocturnal habits have kept H Venatoria from becoming extinct in many tropical locales.

Another big Q in the wash is uncontrolled overpopulation outbreaks in predators. Where a few thousand are usually found, suddenly a few hundred billion pop up for a short span. What effect does those outbreaks have on entire genera in given locales.

Then take the heart of the undisturbed Hasselti's natural environment up in the Kakadu and Arnhemland. According to geologists that area has never been underwater or has experienced a major climatological shift. What we see today is pretty much the way it was 50 million years ago. (Some estimates place it as much as 120 to 170 million years but are usually discounted for lacking evidence) That is an extremely well established and integrated ecosystem. There's checks and balances in effect that we may never fully understand.
 

Widowman10

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I believe the egg sac parasitoids have a much greater impact due to their ability to wipe out the entire sac (as opposed to just a single spider). The outbreaks I would imagine follow the typical fluctuations in prey availability but like you say I'm not sure what the effects would be...

And now you've got me wondering what the checks and balances of that area could be...

Speculation: I wonder if the spike in widow population causes a drop in prey availability, causing females to produce less egg sacs. Much like in captivity where over fed females will continue to drop more sacs but when starved will cease to produce sacs?
 
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pannaking22

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Since we are confusing ourselves anyway, allow me to toss a few more unassigned variables into the works.

I never gave much thought to parasitoids having an extreme overall effect of spider populations until I came here. At any given time I could check out our own house and the surrounding few acres and find several dozen mud wasp incubators with at least one spider victim in each. That the wandering/hunting spiders survive here at all is pretty amazing. Mostly like only their nocturnal habits have kept H Venatoria from becoming extinct in many tropical locales.

Another big Q in the wash is uncontrolled overpopulation outbreaks in predators. Where a few thousand are usually found, suddenly a few hundred billion pop up for a short span. What effect does those outbreaks have on entire genera in given locales.

Then take the heart of the undisturbed Hasselti's natural environment up in the Kakadu and Arnhemland. According to geologists that area has never been underwater or has experienced a major climatological shift. What we see today is pretty much the way it was 50 million years ago. (Some estimates place it as much as 120 to 170 million years but are usually discounted for lacking evidence) That is an extremely well established and integrated ecosystem. There's checks and balances in effect that we may never fully understand.
Hooray for extra variables! The parasitoids that go after larger ctenids and sparassids must be pretty intense. I remember someone recently posting a vid here on AB that showed a tarantula hawk trying to take a Phoneutria and both ended up dying in the end.

Arthropod population booms and busts must lead to very interesting ecological dynamics in the tropics, though I wonder if they would at least be somewhat predictable based on seasonality. Like during June you can't even look at a wall without scaring up several dozen small venatoria. Here in Illinois, we at least know that once we get a good rain, mosquito populations will skyrocket in about 7-10 days.

Well, I guess I'll be moving to Australia then after I defend my Master's tomorrow...gotta do something with my time, right? :D

Speculation: I wonder if the spike in widow population causes a drop in prey availability, causing females to produce less egg sacs. Much like in captivity where over fed females will continue to drop more sacs but when starved will cease to produce sacs?
I also wonder what the relationship between prey quality and egg number/sac size/sac number would be.
 

alfiebass34

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There's a section on my site about breeding, cruise through that if you'd like.

I've introduced males several ways, and they were almost all positive. The female seems to know pretty quick that it's a male, and the male can sense the pheromones on her web, so he knows what's going on too. L. hasselti females aren't really more aggressive than others, and it's slightly misleading to say they "eat the males." Rather, the males "offer" themselves to the females to be consumed. It's a very interesting reproductive strategy. I've had luck not varying temps from different species to drop sacs, many from different climates. Who knows if I would have had even more "luck" had I done that? My room did fluctuate in temperature with the seasons though, so that helped I'm sure. I live in Colorado (where it's very dry) and they have thrived for me. I do mist the web every few days or weeks so that they can get moisture though. You can tell when a widow needs moisture and when it doesn't. It's not a science, more of an art ;)

Are you working with any other exotics besides pallidus right now?
Where is your site Widowman ??
 
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