Oribatid Mites on White Spotted Sawyer - everyone on the bus!

Orbatid mites, also called beetle mites, hitching a ride on a white-spotted long-horned beetle.

We use horses, donkeys, and ostriches to hitch a ride on, taking us from one location to another.  Such relationships are also common in the animal world between different species.  Orbatid mites, also called beetle mites, belong in this category in that they may attach themselves to certain beetles for a ride.  But, instead of it being just one or two of them, as is often the case, there may be dozens or even hundreds.  From the outside, it looks like the beetle may be parasitized, but the strange thing is, it isn't.  It turns out that this is a commensal relationship.

Commensalism is a relationship between two species where one benefits (in this case, the mite) while the other remains unharmed (the beetle).  Other than weighing the beetle down a bit, which really doesn't hurt it much at all, there is no harm.  Some beetles get covered from front to back.  The mites do not harm the beetle, do not prevent it from its normal activities, and may leave the beetle at some point to go on with its business, free of the little hitchhikers.

Orbatid mites feed on fungi, bacteria, and decomposing plant material.  They are a diverse group of spider-related (arachnids) invertebrates that are found throughout most of the world.  They are not harmful; in fact, they are quite beneficial in that they help with nutrient cycling and soil fertility.

If you want to read more information on these mites, including seeing enlargements of them, click here.

Thanks for reading.

Eric Svendsen     www.ericspix.com