The black widow – a spider known for having a poisonous bite, unique colouring, and -believe it or not- sexual cannibalism (Figure 1). Although not all species of black widow females consume their mates and not all spiders who consume their mates are black widows, it is a potential outcome of mating between these spiders. With that being said, you’d assume that black widow males are not necessarily jumping to find a lover (even if most widows actually don’t cannibalize their mates). However, it turns out that not only are male black widows highly interested in mating, but competition is so fierce that males will often sabotage each other to make the ultimate darwinian sacrifice.
Figure 1. A female black widow spider Latrodectus mactans.
Before we delve into some of the ways that males undercut each other, we need to understand the black widow mating ritual.
Courtship in spiders is not exactly like in humans, instead of funny jokes and compliments, the way to a black widow’s heart is through smell. The female spider will release species specific chemicals called pheromones onto her web to attract a nearby mate. However, once the male has traveled to meet on the web, his hardships are not over and he must begin to impress the potential suitor through dance.
Now, why dance? Seeing that widow females are much larger in size to their counterpart, the male needs to send specific patterned vibrations through the web to the female to catch her attention (Figure 2). This twerking of sorts will ensure that the female spider knows that he is there for love and not lunch.
Figure 2. Male and female widow spiders
However, this dance is not simple and courtship can last for over an hour, which means that all this effort may be all for nothing if another suitor shows up to the party. It is actually the male spider that will have brought this upon himself, leaving a silk trail behind when on the search for his mate. What happens is that other males can simply take this already created, direct path that leads them to a potential female mate.
That means that even if a suitor doesn’t get there first, he can get there easier and faster and still has a shot! A study at the University of Toronto, in Dr. Andrade’s lab, found that 95% of male spiders choose to follow another males path even when they detect the pheromones of a female spider.
Clearly- for lack of a better word- that sucks. Even if you are first, that doesn’t guarantee you a victory. However, that’s not to say that being first does not have its own advantages. Other studies have found that male spiders who arrive at the web first begin to take down the female’s web. Although there are many hypotheses for why this occurs, one hypothesis is that the pheromones from a lustful black widow are different than a hungry one or are impacted by the pheromones from the male. So by destroying her web, and letting her remake it when satiated, the pheromones she will produce will be different.
So although the love life of black widow spiders are still under study,- it should be noted that if you think your love life is complicated – think again.
By Sloane Kowal
Please note that opinions expressed are the author’s own. They do not necessarily reflect the views and values of The Blank Page.
