Brachypelma tarantulas are recognized throughout the world as some of the most beautiful and sought after spiders.
It is widely believed that captive breeding is the only way to ensure the future of Brachypelma, both in the hobby and in the wild. The demand for them is such that the prices for adults are very high and this puts them at risk from smuggling, which does happen, despite the efforts of CITES and those dedicated to their preservation, colonies are being stripped to be sold to ‘gringos’ for a few pesos.
The sad fact is that what is worth a few pesos to a local in Mexico is worth many dollars outside of Mexico.
With the growing interest in spider keeping in Mexico, it is becoming fashionable to get just one spider as a ‘mascot’, it is reported that many back street traders have been found to have many adult spiders in plastic bags, many suffocated, or dead from dehydration. These spiders are taken from decreasing colonies, only the adults are taken, by doing so it is wiping out a lot of reproductive capacity in the wild stocks, baring in mind that it takes years for them to reach breeding maturity, it wipes out years of reproduction. Then there is the native fear of spiders, they have years of ingrained fears, so believe they are deadly to humans therefore they kill them.
There are many dedicated Mexicans who are trying to make a difference to preserve their native fauna, not only tarantulas, and we need to help them in their efforts. So we have to breed in captivity with the stocks we have, if we can do this it will supply the needs and make Brachypelma easy to obtain without wild stock being affected.

They are difficult to breed in captivity, the average success rate is estimated at around 1% of matings result in spiderlings. Much of this I suspect is just due to a casual try at mating. But even serious attempts of breeding have many variable difficulties.
Is the male fertile? Is the tank too wet/too dry? Too hot/too cold? Does feeding make any difference, do they need variety? Is it light levels that count, hours of daylight? Do they need to mate more than once? Will they eat the egg sac if disturbed? Why do egg sacs go bad?

Getting an egg sac is a result, getting that to spiderlings is difficult.
Then the question is whether to leave the egg sac with the female or to remove it and artificially incubate, then at what point would you remove it?
The important points seem to be getting the spiders seasoned , having a freshly moulted female and a freshly moulted fertile male, in the right season.
There is little recorded information on long term study and repeatable success for breeding of Brachypelma.
The following pages hope to shed some light on what does work, and what can, and so often does, go wrong.

Where to start

First you need to ensure you have a male and female of the same species, or colour form.

There are some species that do look very similar, mainly the ‘red rumps’, vagans, sabulosum, angustum and epicureanum. Also similar are annitha and smithi. If you are not certain they are the same species then do not attempt to mate them. The result of such cross breeding could be the loss of true species in the hobby.

It is commonly believed that this is what has happened with the ‘red rumps’ species, they have been crossed with each other so all we have now in the hobby are hybrids. Whether this is due to ignorance or deliberate act is not known, but to find a true type is practically impossible.

It may well be proven that most of Brachypelma genus are, ‘colour forms’, but even if that is the case they should not be crossed. I see no point in doing so, after all if you want, an annitha for example, you should get an annitha. Nature has provided us with these amazing creatures and to mess with their make up defeats the object. It has happened with so many creatures, man finds, man changes, man ruins.

So I would say if you want to keep what we have, keep the mating true to type, whether that be species or colour form.

Hopefully in the future we will be able to re instate the ‘red rumps’ back into the hobby in their true types. We do not want to lose any more to cross breeding.

The easiest way to determine the sex of a tarantula is from a moulted exuvium. The female has a spermathecae, the leaf like structure between the top book lungs.

A female will be mature at approx 5 inch leg span, though not fully grown, any smaller than this and the spermathecae will not be fully developed and the furrow will not be open.

A mature male will have tibial spurs on leg one and the end of the pedipalps have bulbs (look like boxing gloves). If these are not present he is not mature, once mature a male will not moult again

If you don’t have any moults?

On the ventral view it is possible to see the opening of the spermathecae on a mature female, this appears as a flesh coloured line between the book lungs, on a male the area between the top book lungs is narrow and appears more arched in shape there is no flesh coloured line as there is no opening there.

From a side view the female appears to have a pot belly, where a male is flat.

The timing of mating is quite important. The optimum time for mating is just after the female has moulted, with a fresh male who has made a sperm web. I have found that females mated more than three months after a moult will not produce an egg sac but will moult again, though having said that it is still worth trying if you have an available male.

When you have your male and female you want to see if they are ‘interested’ in each other. I always put the male in a secure plastic tub and place that tub in the females tank

The tub should be big enough for him to move around freely and contain some substrate.

I would leave them to settle for an hour or so, then look in and see if they are reacting to each other.

I have found the best times for action is early morning or evening. The usual reaction if they are willing would be dancing and drumming.

The male will tap with his legs and pedipalps, then he will flex up and down quickly, rather like press ups, he will pause in between these actions to wait for the females response.

The female will tap with her front legs then she will drum very quickly, (this sounds like an electric toothbrush, if you put it down on a work surface).

The female also has active control of the epigastric furrow, so if she opens the furrow that is a sure sign she is ready for mating. She will usually go towards the male or turn in his direction.

If all the signs are good then I remove the lid from the males tub and sit back and watch

The male will walk around the walls of the tank .I suspect this is so he can familiarize himself with the surroundings so he can make good his escape after the mating. When they are responding well to each other the male will approach the female,

Now he has completed the mating he will carefully back away whilst still holding her fangs, then he will release the fangs and make a quick retreat. At this point the female may try to follow after him but usually stops without attacking him. I always keep a smooth stick on hand,( the long handled artist paint brushes are ideal), just in case, so I can put it in between them whilst he makes good his escape.

The best policy I believe is to help the male out of the tank using a cut off bottle, then put him back into his own tank.

The female will usually be very active for some time after the mating, checking around her tank.

I always feed them directly after mating, both the male and female.

If they show no interest in each other then I would remove the male from the females tank and try again in a day or two. If there is still no interest, then the chances are they will not mate. This could be because the female is too far through her cycle or because the male is no longer fertile. But you can still try, never say never.