Spiders have been around for millions of years, yet there’s still so much we don’t know about them. Recently, researchers made an exciting discovery about how spiders smell, particularly male wasp spiders.
A study published in the Proceedings of the National Academy of Sciences found that male spiders have special hairs called wall-pore sensilla on their legs. These act like a nose, helping them detect scents released by female spiders.
This finding resolves a mystery that has puzzled scientists for over a decade. Researchers have now identified and mapped these sensilla, opening the door to more studies on how spiders smell.
Although spiders are known for their sensitivity to vibrations and some, like jumping spiders, have great vision, their sense of smell had not been well understood. While there is evidence that spiders can pick up on odors like sex pheromones, two major questions remained: What do spiders use for smelling, and how do they smell without typical structures found in insects?
This new research answers both questions. It shows that male wasp spiders have wall-pore sensilla, allowing them to detect airborne pheromones very effectively. Surprisingly, these sensilla are not just found in wasp spiders, but are common among many spider species.
To investigate further, researchers used high-resolution scanning electron microscopy to look closely at male and female wasp spiders. They discovered that male spiders have thousands of these sensilla on their legs, and they are different from what is found in insects.
The wall-pore sensilla are located on the upper part of the male spider’s legs, away from surfaces they touch often. This suggests that their main job is to sense airborne odors, especially during mating.
To test the capabilities of these sensilla, scientists exposed male spiders to sex pheromones under a microscope. They found that even a very small amount of pheromone could trigger a strong response in the sensilla, indicating how sensitive they are to these chemical signals. This sensitivity is on par with the best smell detection systems in insects, which is remarkable.
The researchers didn’t stop with just the wasp spider. They looked at 19 other spider species and found that wall-pore sensilla were present in many of them, specifically in males. However, some older spider groups, like the basal trapdoor spiders, do not have these structures. This suggests that wall-pore sensilla evolved multiple times in spider evolution and were lost in some lineages.
This study opens up new questions about spider biology. How do female spiders smell without these sensilla, and what other chemicals can spiders detect? Understanding the molecular and neural basis of spider smell could reveal how their sense of smell has developed through evolution.
With so much still to learn, the future of spider research looks promising. These discoveries highlight the complexity of these often-misunderstood creatures and their ecological roles.
Dan-Dan Zhang, Researcher of Sensory Biology, Lund University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Source link
spiders
