Thursday, October 4, 2012

Spider Mating and Reproduction

In order for a male spider to mate with a female, he must first inform her of his presence and his intentions.  He would normally do this by tweaking and strumming on her web in a certain way that only a female of the same species would understand.  Once he is convinced that she is aware of him he can approach her.  Depending on the species, the male may then have to perform another dance or present the female with a “gift” in order to preoccupy her so that she does not eat him.  Others may have to use “tactile communication” – stroking the female’s legs – to get her “in the mood”.
Once the female is ready to mate, the male must first deposit his sperm on to the web or substrate.  He then picks up the sperm with his pedipalps and inserts them one by one into the female’s genital opening (epigynum).  The male and female of one species have perfect fitting reproductive organs like a lock and key, so that two different species can never copulate.
The males of several species of spider must retreat quickly once mating has taken place to avoid being eaten by the female. The most famous of these are the “widow” spiders (Latrodectus spp.), named after this behaviour.  However, the males and females of many other species cohabit amicably in the same web with no threat of cannibalism.
Araneomorph spider females can often store up eggs and sperm and fertilize them when they are ready.  Even after they moult (Ecdyse) they still keep the same set of eggs and sperm.
Mygalomorph spider females, however, replace the lining of their reproductive organs every time they moult, making them “virgins” again after each ecdysis.
Above: Latrodectus geometricus - BROWN BUTTON (WIDOW). The most famous examples of spider females eating their male partners after mating are the Widow spiders, but the males of many other species must also rush to escape the same fate.  However, not all spider species practise post-sex cannibalism!


  1. Hi,

    keen to find out more about Kenyan spiders - ientification and treatment of bites. Is there a reference book/field guide or expert at the Museums of kenya?



  2. Hi John,

    Thanks for your interest. There is currently no book on spiders in Kenya, which is partly why I started this blog. You can get books on Southern African Spiders, and the information on bites will be very much applicable to Kenyan spiders (as many of the same families and genera occur in both areas).
    I would recommend "Spiders of Southern Africa" by Astri and John Leroy, and/or "Filmers Spiders: An Identification Guide for Southern Africa" by Martin Filmer and Norman Larsen.

    The best book probably (but very difficult to find) is: "African Spiders: An Identification Manual" by Ansie Dippenaar-Schoeman. No colour photos, though. But lots of very good info and line drawings. Very extensive coverage of all Afrotropical Spiders.

    At the National Museum, you'd have to get in touch with the Zoologoy - Invertebrate section to find out more, but I believe you have to write a research proposal in order to access much of their information.

    Hope that's helpful to you!