Pest of the month: The Pine Oribatid

During my residence at Fujikawa Kouka-en I was told of a pest mite regularly found on pine bonsai. With the help of my teacher I got hold of a specimen. Back in Sydney, armed with a microscope, thick books and the Internet, I managed to identify it as the Pine Oribatid (Diapterobates humeralis). It’s an arboreal mite that feeds on decaying plant tissues, fungi, algae, and lichens in coniferous forests. For what it’s worth it “cleans” the tree bark off fungi, algae, and lichens. It also feeds on silk filaments enveloping the eggs of woolly conifer aphids (see my blog post about a similar aphid here http://lomov.blogspot.com.au/2013/10/pest-of-month-asian-woolly-hackberry.html). By doing that it dislodges the eggs and exposes them to the elements and the natural predators such as ants and spiders. This means that the Pine Oribatid is not a pest, but one of the good guys!