Scientists have described how a species of insect lures spiders by mimicking prey caught in webs.
Assassin bugs plucked the web's silk threads that replicate the vibrations of a fly or other insect, causing the fooled spider to head towards the bug.
Once within reach, the bug slowly tapped the spider with its antennae before lunging and stabbing the lured arachnid with its sharp snout.
The findings appear in the journal Proceedings of the Royal Society B.
The team from Macquarie University, Australia, said the behaviour - known as aggressive mimicry - was one of two strategies employed by the bug (Stenolemus bituberus) to trap its prey.
The other involved stalking spiders, where the assassin bug slowly approaches the unsuspecting victim until within striking range.
The researchers, Drs Anne Wignall and Phil Taylor, explained that the bug exploited web-building spiders' use of vibrations to detect and locate its prey.
However, reliance on vibratory cues and predictable responses leaves web-building spiders vulnerable to predators that aggressively mimic prey stimuli to gain control over their behaviour, they wrote.
If you imagine an insect such as a fly when first hits the web, it'll generate a huge intial vibration, and then it will begin struggling violently, buzzing its wings, explained Dr Wignall.
During these first vibrations, the risk of the prey escaping from the web is largest, and so spiders will tend to move in quickly on prey producing these sorts of vibrations in the web.
But, as time goes on, an insect may get more tired, and the vibrations it produces will be much smaller. The spider can take more time approaching these insects as it's less likely to escape from the web, she told BBC News.
These are the sorts of vibrations assassin bugs are mimicking, and it makes sense as a spider is very dangerous prey for a bug. If the spider approaches too fast, the risk to the assassin bug is much higher.
The assassin bugs, distributed throughout Australia, are often found on tree trunks, in both suburban and bush areas.
The insects live for about a year, and spend all their lives in spider webs - feeding, resting, mating. If they're not in a spider web, then they're usually travelling toward another spider web.
Full story and link: http://www.bbc.co.uk/news/science-environment-11628322
