Nav: Home

Nuptial gifts beat pheromones

March 01, 2018

Unlike many other species, male hunting spiders do not use chemical signals such as sex pheromones to attract a mate. Instead, they make their mark by uniquely exploiting a female hunting spider's interest in food. Research led by Cristina Tuni of the Ludwig Maximilian University in Munich in Germany now shows that male hunting spiders wrap morsels of food in their silk and offer these as gifts to prospective mates. The study is published in Springer's journal Behavioural Ecology and Sociobiology.

Many previous studies have examined the role that sex-specific pheromones or semiochemicals play in the evolution of a spider's reproduction cycle. Pheromones can be emitted both from a spider's body and from its silk. This form of chemical messaging allows for long-distance air-borne, or direct communication between spiders, and enables them to locate a mate, distinguish between males and females, or decide on the suitability of a potential partner.

Among web-building species, females living on webs rely on their pheromones to be carried through the air so that potential males can determine their whereabouts and learn more about their sexual maturity and mating status. Webless wandering species such as the hunting spider (Pisaura mirabilis) often depend on so-called draglines which hang, for example, from branches. These draglines are important not only for movement, but as part of the process of searching and attracting mates. Males also use their silk in another way: they are among only a few species that offer nuptial gifts of prey wrapped in dense layers of silk to females, to be eaten during copulation.

Tuni and her colleagues conducted a series of experiments on around 100 spiders (Pisaura mirabilisi) to test whether the silk that male and female hunting spiders produce is an important part of mating, and if sex pheromones are always released.

The study revealed that male and female spiders do not have the same reaction to silk. Males were attracted to the draglines that females produced. According to the researchers, this suggests that there are chemical cues attached to these silk draglines, and these likely serve as a form of female advertisement. Signalling through draglines may also be a way for females to supplement their own efforts to find food, because it lures would-be gift-carrying mates.

Quite unexpectedly, the researchers found that females had no interest in the draglines that males produced, nor the silk that they used to wrap nuptial gifts in. This suggests that male hunting spiders do not release chemical signals.

"This suggests that males rather may be uniquely exploiting females' interest in food through their gift-giving behaviour," says co-author Michelle Beyer, who adds that females might also have learnt to ignore chemical signals, because males deceive them about the quality of the food hidden in the silk-wrapped gifts presented to them.
-end-
Reference: Beyer, M. et al (2018). Does silk mediate chemical communication between the sexes in a nuptial feeding spider? Behavioral Ecology and Sociobiology DOI: 10.1007/s00265-018-2454-1

Springer

Related Spiders Articles:

Freshwater insects recover while spiders decline in UK
Many insects, mosses and lichens in the UK are bucking the trend of biodiversity loss, according to a comprehensive analysis of over 5,000 species led by UCL and the UK Centre for Ecology & Hydrology (UKCEH), and published in Nature Ecology & Evolution.
Cave fights for food: Voracious spiders vs. assassin bugs
Killing and eating of potential competitors has rarely been documented in the zoological literature, even though this type of interaction can affect population dynamics.
Spiders and ants inspire a metallic structure that refuses to sink
University of Rochester researchers have created a metallic structure that is so hydrophobic, it refuses to sink - no matter how often it is forced into water or how much it is damaged or punctured.
Compact depth sensor inspired by spiders
Inspired by jumping spiders, researchers at the Harvard John A.
Researchers find hurricanes drive the evolution of more aggressive spiders
Researchers at McMaster University who rush in after storms to study the behavior of spiders have found that extreme weather events such as tropical cyclones may have an evolutionary impact on populations living in storm-prone regions, where aggressive spiders have the best odds of survival.
Baby spiders really are watching you
Baby jumping spiders can hunt prey just like their parents do because they have vision nearly as good.
Solitude breeds aggression in spiders (rather than vice versa)
Spiders start out social but later turn aggressive after dispersing and becoming solitary, according to a study publishing July 2 in the open-access journal PLOS Biology by Raphael Jeanson of the National Centre for Scientific Research (CNRS) in France, and colleagues.
Spiders risk everything for love
A biology study finds that blue jays can easily spot wolf spiders engaged in their courtship rituals.
Hold the mustard: What makes spiders fussy eaters
It might be one of nature's most agile and calculating hunters, but the wolf spider won't harm an insect that literally leaves a bad taste in its mouth, according to new research by a team of Wake Forest University sensory neuroscientists, including C.J.
Giant Antarctic sea spiders weather warming by getting holey
Scientists have wondered for decades why marine animals that live in the polar oceans and the deep sea can reach giant sizes there, but nowhere else.
More Spiders News and Spiders Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Uncharted
There's so much we've yet to explore–from outer space to the deep ocean to our own brains. This hour, Manoush goes on a journey through those uncharted places, led by TED Science Curator David Biello.
Now Playing: Science for the People

#555 Coronavirus
It's everywhere, and it felt disingenuous for us here at Science for the People to avoid it, so here is our episode on Coronavirus. It's ok to give this one a skip if this isn't what you want to listen to right now. Check out the links below for other great podcasts mentioned in the intro. Host Rachelle Saunders gets us up to date on what the Coronavirus is, how it spreads, and what we know and don't know with Dr Jason Kindrachuk, Assistant Professor in the Department of Medical Microbiology and infectious diseases at the University of Manitoba. And...
Now Playing: Radiolab

Dispatch 1: Numbers
In a recent Radiolab group huddle, with coronavirus unraveling around us, the team found themselves grappling with all the numbers connected to COVID-19. Our new found 6 foot bubbles of personal space. Three percent mortality rate (or 1, or 2, or 4). 7,000 cases (now, much much more). So in the wake of that meeting, we reflect on the onslaught of numbers - what they reveal, and what they hide.  Support Radiolab today at Radiolab.org/donate.