The Solution to the Worlds Waste Problem- Mealworms?!

I’m sure that many- if not all- of the people that read this blog would, like me, firmly believe that pollution is an incredibly serious issue which has been dangerously ignored and cast aside by previous generations. This seems to me to be especially true of physical pollution from litter (especially non-biodegradable plastics) – an area of the issue that seems to have been further ignored in favour of dramatic pictures and headlines regarding global warming, and the plight of the (admittedly much more photogenic) polar bears. This makes it all the more heartening to read that, at long last, there is a potentially promising solution to the massive deficit of plastic pollution that has been dumped in landfill sites all over the world- and it comes in pretty much the most unlikely form possible.

The research in question has been undertaken by scientists at Stanford University in the U.S., in collaboration with researchers in China, and has discovered that the unassuming mealworm (the larvae of the darkling beetle) is capable of thriving for at least a month on a diet of pure polystyrene1. 100 mealworms have been proven to dine on between 34 and 39 milligrams of polystyrene a day under lab conditions, to produce just CO2 and a small amount of tiny, biodegradable droppings (a process neatly summed up in an “infographic” created by the research team)1.Mealworms infographic

Although this is a tiny amount, it is undeniably excellent news- especially considering at present no polystyrene has been in existence long enough to have decomposed naturally2. This breaking down of the polystyrene is possible due to microbial action in the gut of the mealworms (as demonstrated by the fact that the meal worms were unable to digest the polystyrene after being fed a diet containing antibiotics), most likely the YT2 strain of Exiguobacterium– which has since been shown to form “noticeable pits and cavities”3 when left on a piece of polystyrene.

As the research supervisor, Craig Criddle, stated- “Sometimes, science surprises us. This is a shock.” In my view, this comfortably sits alongside Jeremy Corbyn’s victory and the discovery of water on Mars as one of the most shockingly great news stories of 2015- but if you feel differently, please feel free to comment (Harriet)!

 

Sources:

 

1 http://pubs.acs.org/doi/abs/10.1021/acs.est.5b02661

2 https://www.csuohio.edu/sustainability/fun-stuff-and-fast-facts

3 http://pubs.acs.org/doi/abs/10.1021/acs.est.5b02663

 

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Grimbiosis 2: The Green-Banded Broodsac

rsz_boogly_snail_1   This groovy-looking, mind-controlling, gender-bending parasite is potentially the only creature alive that can make this author feel sorry for snails. The green-banded broodsac (Leucochloridium paradoxum) begins its life as a microscopic but incredibly hardy egg, spawned by the adult broodsac, which lives relatively harmlessly within the digestive tract of a shore bird. Like a tiny, dirty paratrooper, the egg is eventually excreted by the bird, and this is the stage at which the “grimbiosis” really begins.

If this egg is “lucky”, a very unfortunate snail will discover the birds’ faeces and in (disturbingly) the least disgusting part of the cycle, consume it. The tough eggs are indigestible by the snail, and so can easily spread around the snails’ digestive tract. The eggs then hatch into the larval stage, the miricidia, which thrive in the gut- but these mobile horrors aren’t content to merely thrive- and so they begin to spread around the snail, with especially successful larvae finding their way to the snailsrsz_1broodsac eye-stalks. They then metamorphose into immobile sporocysts, and begin to rapidly reproduce, forming the undeniably alien looking “broodsac”. For some unknown (but presumably malicious) reason, the broodsac seems to prefer the left eye stalk, though it is not uncommon to find an infected snail with a broodsac in each eye stalk. Once the broodsac is sufficiently, horrifically, large, the many sporocysts will cease reproducing, and instead metamorphose into cercaria (the first form in which they are able to infect a bird), and encyst themselves (become dormant within a hard “shell”) in order to prepare for their long journey.

This is where the uniquely malevolent nature of the green-banded broodsac comes into play. Rather than waiting patiently and hoping that the snail is eaten by a bird, this nasty parasite instead infects the snails miniscule brain, and alters its behaviour- causing it to seek out light rsz_boogly_snail_2areas, therefore exposing it to a greater number of predatory birds. On top of this, the now large and brightly coloured broodsac begins to pulsate when stimulated by light, making it almost indistinguishable from a large grub or caterpillar- an enticing meal for any passing birds. This concept is known as “aggressive mimicry”, and is surprisingly rare among parasites.

The flamboyant, light seeking snail is then usually, and unsurprisingly, eaten by a bird- and so the horrific cycle can begin again; and, to top it all off, in classic Grimbiosis style, the creature is monecious- meaning it has no gender and is free to reproduce with any of its peers. This seemingly unstoppable parasite is truly horrific and, admittedly, far more disgusting than the average snail.

Sources:

http://link.springer.com/article/10.1023/B:SYPA.0000003809.15982.ca

http://www.wired.com/2010/05/process_snail/

http://link.springer.com/article/10.1007/BF00009845#page-1