They briefly exposed the mites to very low humidity, allowing some of the males to cluster while keeping other males in isolation, and then compared water loss between the two groups. Isolated males lost nearly twice as much water as their clustered counterparts: 2.63 percent of their total body moisture versus 1.48 percent.

Glass said that mites continue to cluster even when moisture levels in their environment become favorable.

“Humidity in our lab colonies is high enough for the mites to survive quite well, but the mites cluster anyway. We think they expend less energy gathering water that way,” said Glass.

Why should clustering be more beneficial to males than females? The researchers said that males don’t seem to be as hearty as females. Females live for about 90 days, approximately twice as long as males.

How male mites find each other is also somewhat of a mystery. Glass speculates that pheromones may play a role. Dust mites secrete a number of different chemicals, but nobody knows for sure whether any of them are pheromones. Scientists have thus far only identified the role of one of these chemicals -- a compound that inhibits mold growth.

“A number of mites and ticks use pheromones and other chemicals,” said Glass. “They have a whole series of chemical cues, for finding mates for example, or for sounding an alarm. It seems reasonable to think that dust mites utilize chemical communication too.”

If dust mites do indeed use pheromones to find each other, researchers may be able to interrupt the clustering instinct by interfering with these pheromones. Then mites that are unable to cluster could dry out and die on their own, eliminating the need for traditional mite-killing insecticides.

“Typical places to find mites are the mattress, and the carpeting next to the bed, because the bed is where we spen
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Contact: Glen Needham
Needham.1@osu.edu
(614) 688-3026
Ohio State University
25-May-1998