The enemy within

Last week after two years and six postponed dates the Spider presentation finally happened. The talk contained many examples of spiders as predators: building webs, ambushing prey. But spiders don’t always get things their own way. They are an integral part of the food chain which means they are often ‘the hunted’. One of the photos shown (pictured left) taken by JB from Limestone shows the insides of a mud wasp nest that had been accidently knocked off a wall. The nest contained several paralysed spiders placed there by the adult wasp. On these spiders eggs had been laid with the intent that when the wasp larvae hatch the spiders would provide fresh food. On one of the spiders you can even see a wasp larva.

I thought that was as gruesome as the night would get until in a discussion after the talk with another JB (from Killingworth) photos and a video were revealed showing a Redback Spider (Latrodectus hasseltii) walking on a carpet (pictured right). When squashed the spider erupted into a ball of writhing worms (pictured below). Alien eat your heart out!

The worms are endoparasitic Mermithid Worms. The worms enter the spider directly or through what the spider eats and they proceed to feed on the internals of the spider without killing it.  The spider becomes more and more debilitated until the worms burst out of the body and the spider dies. Because in the final stage of the worms’ lives they are aquatic, before the spider dies the worms induce thirst in the host so that the spider will head towards water. That is probably where the hapless arachnid was going on its trip across the carpet.

I’m not going to upload the video but no sci-fi movie comes close to what happens in nature.