Red Palm Mite

Image: Eric Erbe, Chris Pooley
Raoiella indica

Uh oh! Sometimes big problems come in teeny-tiny packages!

And they seldom come teenier or tinier than a Red Palm Mite.

Image: E. Erbe, E. Kane, & R. Ochoa, Usda-Ars

So how tiny are they? The answer is: very. Females can reach about 0.3 mm long at most. That's about the size of a grain of salt. Males are even smaller at some 0.2 mm, which is simultaneously almost exactly the same size and almost exactly half the size. There's not a lot of leeway when you're this small.

They're so incredibly titchy you need some pretty advanced technology to really see how strange they look. Red Palm Mites are very red, rather flat, and covered in a bizarre array of what look like awful fungal growths from a bad attack of Cordyceps. Not that there's such a thing as a good attack of Cordyceps.

Image: USDA

You might wonder what kind of trouble such a tiny little beastie could possibly cause, especially when you realise that their lifespan is typically only about six weeks.

The problem is they eat palm trees. Not all in one go (that'd be a sight), but cell by cell. They plunge their pointy mouthparts into a leaf and suck out the fluid, one cell at a time.

Once you get yourself a good (bad) number of them on a leaf they can start doing serious damage. Leaves turn yellow from the onslaught and coconuts and flowers may fail to grow. It's worst on the little ones, where some reports indicate that a heavy infestation can outright kill a young tree-to-be.

The mites don't dilly-dally when it comes to boosting their numbers either. A female will lay something like 30 eggs in her short lifespan. It's not a vast amount, but it's enough. She needn't even mate; she'll lay eggs either way. If the eggs are fertilised, females will hatch out. If she hasn't mated they'll be males instead. It's a great way to start up new colonies, which is good (bad) because Red Palm Mites are so tiny they can drift away on the wind to find new, juicy leaves to ravage. Walking there is no fun when you're mite-tiny.

Video: Cool Video

They have others ways of travelling, too. Ways that have allowed them to travel across half the world.

Red Palm Mites are native to tropical areas from Egypt to India, but in the mid 2000's they were discovered on the Caribbean island of Martinique. They probably got their via trade and travel, but since then they've spread from island to island, presumably on the wind. Now they've made it to Mexico, Florida, Venezuela and Brazil. There are lots of palm trees there, and it turns out Red Palm Mites find banana trees quite palatable, too.

Gosh. Forget about nanobots and their grey goo. It's all about the Red Palm Mites and their yellow leaves.