Webbing is an often-discussed topic regarding tarantulas, so it’s natural to want to know if one sex has a higher tendency to create more web.
Both female and male tarantulas web in similar amounts while they are immature, and the amount will vary based on which species you have. However, there are noticeable differences in webbing once the males reach their ultimate molt. A mature male will often abandon maintaining the web in his enclosure and begin pacing in search of a mate.
Do all tarantulas create webbing?
All tarantulas can create webbing, however, not all species will copiously web their enclosure. In fact, you may never see some species lay down any web outside of feeding time.
For example, none of my Aphonopelma put down any visible webbing outside of their burrows, but I can see it lining the walls of the burrow if look really closely. I don’t recall every seeing my G. pulchra make a web. In contrast, all of my Dolichothele diamantinensis females and juveniles heavily blanket everything in their enclosures with webbing as long as they have enough spots to anchor the web.
Why do tarantulas make webs?
One of the primary ways that tarantulas use webbing is to create their homes. They line their burrows to prevent the substrate from collapsing, and some will make elaborate web tunnels that completely fill the entire enclosure if you give them enough anchor points. Arboreals will make vertical web tubes, web hammocks, and dirt curtains (thick sheets of webbing with dirt stuck in them).
Tarantulas also use their webbing to secure prey while they’re eating. You’ll often see your spider doing a “happy dance” after catching something, where it continues to spin in a circle bobbing its abdomen up-and-down and from side-to-side. This is the tarantula putting down web.
Molting mats are another important way that tarantulas use their webbing. A molting mat is a thick web that a New World tarantula lays down prior to molting. They cover it with a layer of their urticating hairs to keep them protected from potential predators while they are vulnerable.
Female tarantulas use their webbing to create egg sacs, and mature males create sperm webs.
What is a sperm web?
Once a male tarantula reaches his ultimate molt, he is ready to begin looking for a mate. He will need to create a special web using his epiandrous fusillae so that he can collect the sperm with his emboli (at the end of his palpal bulbs), which he will eventually use to deposit the sperm inside the female if given the opportunity. The palpal bulbs are located at the tips of both his pedipalps.
Male tarantulas have miniature spigots called epiandrous fusillae located near the ventral furrow, which is underneath the spider at the top of the abdomen. These spigots are specialized and they only produce the silk that the male uses for his sperm web.
How do you know if a male tarantula has made a sperm web?
It can be difficult to know if your male has made a sperm web because they tear it down when they’re finished loading their palps. You can sometimes see a rolled-up ball of thick webbing on the substrate with species that don’t heavily web their enclosures, or a thick line of web hanging from the side of the enclosure. However, it’s nearly impossible to distinguish the remnants of a sperm web from the rest of the webbing in a species that already has a heavily webbed enclosure.
If you’re lucky, you may catch your male in the process of loading his palps, also known as “charging” his palps. While he’s transferring the sperm into his palpal bulbs he will repeatedly drum his pedipalps against the webbing.
Terrestrials will usually place their sperm web in a corner of the enclosure, and it will look like a hammock that is suspended in the air above the substrate, often starting at the enclosure wall and going down to the substrate (if you see a thick web mat on the surface of the substrate that is a molting mat). Arboreal species will often create their sperm webs on the sides of their enclosure. Terrestrial males will be flipped over on their backs while they create the web.
How do I get a mature male to make a sperm web?
There’s nothing you can do to force a male tarantula to make a sperm web, he’ll make one when he’s ready. It’s possible that he’s already made one without you knowing it! You can try putting his enclosure next to a mature female of the same species, or taking a small amount of her webbing and placing it inside his enclosure.
Make sure your male has access to water, and that you still attempt to feed him (although many will refuse food after maturing). Some breeders report that their newly matured males will often make a sperm web quickly following a drink and a meal.
Final Thoughts on Male vs. Female Tarantula Webbing
If you’re worried that you’re going to miss out on interesting webbing behavior because you have a male tarantula don’t despair. As long as you’re raising it from a sling, you have a long time to enjoy watching him create fascinating web structures provided that you have a species that webs heavily.