An Australian 'spider fly' Canberra - Arabstoday Four new species of Australian fly turn the food chain on its head - their young actually EAT huge spiders such as tarantulas. Maggots from the 'spider flies' burrow inside the bodies of young spiders - and actually extend their lives, forcing them to live on as immature spiders, never 'growing up' for up to ten years. Eventually, the spider fly maggot will eat the spider from the inside out, leaving behind only the skin. Only then will the spider-fly pupate to develop into an adult. 'They specialize in big spiders like tarantulas. Those spiders can live for years at a time,’ said researcher Shaun Winterton in an interview with Livescience. ‘When they have the maggot inside the spider, it actually extends the spider's life - they can live like that for up to ten years.' The new species were found by Shaun Winterton as part of a review of spider flies in Australasia. Oddly, the adults are important pollinators of flowers - and feed on nectar. The adults typically have large round bodies covered with dense hairs and black or metallic green to blue shells, giving a jewel-like appearance. All species of 'panopinae' spider flies have larvae which eat young spiders. The new species specialise in eating spiders such as tarantulas, trap door and funnel web spiders.