Question of the month

Mighty mites

My daughter found this small fuzzy creature on a bush walk last week and we would like to know what it is and what it eats.

 

Video courtesy of Jillian Coles.

Answer

This mite is probably a species of Mesothrombium.

The furry red creature in your images is a type of mite, called a Red Velvet Mite. These are arachnids, distantly related to spiders and scorpions.  There are at least 55 000 named species of mites, yet this is estimated to only be 10% of those in existence! Mites are found in almost every habitat and environment, and have a great variety of lifestyles. Some are parasites, but others help break down rotting vegetation, or prey on other mites that are agricultural pests.

A Rainbow Mite, found on Mt Glorious. Photo courtesy of Katie Hiller.

Most mites are tiny, less than 1 mm in length. However, you have found one of the giants of the mite world. Red Velvet Mites can be up to 10 mm in length and belong to a group of mites (infraorder) known as Parasitengonina. All members of the Parasitengonina have nymphs and adults that roam in search of prey, commonly the eggs of insects. The larvae are parasites, attaching to a preferred type of host, be it an insect or vertebrate, including humans.  The best known type of larva is the scrub-itch mite, notorious for biting humans.

Adult Red Velvet Mites like the one you have photographed are very mobile. Because of their bright red colouring they are one of the most commonly observed mites. The photographed mite probably belongs to the genus Mesothrombium. We do not know what the larvae look like, or what they feed on, but like all other members of its family it will be an insect or arachnid.

Queensland Museum acarologist (mite specialist) Owen Seeman at work. The grey cases on the shelves house part of the mite collection.

Another large free roaming mite that is sometimes brought into the Queensland Museum is a relative of the Red Velvet Mites. These are “Rainbow Mites” in the genus Rainbowia. Rainbow Mites are common on Eucalyptus trees and laboratory experiments suggest that the larvae parasitise psyllids (jumping plant lice). Despite their bright iridescent colours, Rainbow Mites were not named for this but actually in honour of W. J. Rainbow, a significant Australian arachnologist who was active in the late 1800s and early 1900s.

The Queensland Museum mite collection is mounted on 25 000 slides and is the amalgamation of collections from several institutions; the Queensland Museum, University of Queensland, Queensland Department of Primary Industries, and Queensland Institute of Medical Research.  These slides are kept in the Arachnology lab in slide boxes, shelved and catalogued like books in a library.

More information about mites can be found here.

Queensland Museum's Find out about... is proudly supported by the Thyne Reid Foundation and the Tim Fairfax Family Foundation.

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