Every spring, people notice the presence of little red bugs walking on pavements, sidewalks, stones, or some kind of masonry floor in patios or outdoor walls. These are not insects, but mites and are commonly called concrete mites, cement mites, or sidewalk mites. They can be easily observed with a naked eye and are approximately 1.5 mm in length.
Given the abundance of this mite, I was surprised that there is not much information, and little is known about the biological aspects of this mite and other species in this group. In spring, these mites are typically found moving fast on concrete and stones during dry, warm days. Temperatures of paved surfaces can be high but these mites appear to be tolerant. People notice them due to their conspicuous red color.
These bright red mites are members of the Erythraeidae family; erythr- is a word of Greek origin meaning red (e.g., erythrocytes: red blood cells in humans). These mites belong to the genus Balaustium. Some of the species in this group are known to be pollen feeders as well as generalist predators. Their abundance in spring precisely coincides with the high abundance of pollen during this time of the year.
In a publication by Yoders et al (2012), the authors reported that pollen consumption is done by all the stages of Balaustium sp.: the three-legged larva, the fourth legged deutonymphs, and adults; however, feeding by larval instars may be more important as the presence of microarthropods or honeydew in plants is scarce. In addition, the same study showed that these mites did not show preference for different types of pollen. Aggregation of these mites can occur when they feed on pollen in anthers (Figure 2), prey, or honeydew.
More information is available at
Ohio State University: "Concrete Mites" Are Out: Look Before You Sit! -- https://bygl.osu.edu/node/1588
Kentucky Pest News: Clover Mites and Concrete Mites -- https://bit.ly/3wC3pKT
Categories: Ohio, Rural Lifestyle