ON THE USE OF HUMEROBATES-ROSTROLAMELLATUS (ACARI) AS AN AIR-POLLUTION BIOASSAY MONITOR - THE INCIDENCE OF SO2-NO2 SYNERGISM AND OF WINTER TEMPERATURE

H. rostrolamellatus was exposed to a replicate series of concentrations of SO2, NO2 and combinations of these 2 air pollutants for 168-h periods. These laboratory tests show or confirm the sensitivity of the mite to these air pollutants and demonstrate synergic interactions between SO2 and NO2. Furthermore, transplant experiments were carried out in the field in order to assess the mite sensitivity to SO2 and to monitor air pollution. Daily mean temperatures below -8.degree. C apparently constitute a drawback in the use of this mite as an air pollution monitor. The experiments also contribute to improvements in the accuracy of the dose-response relationship between mite mortality and outdoor concentrations of SO2. Field data combined with the laboratory results indicate that H. rostrolamellatus should be considered as a bioassay monitor of air pollution rather than a mere SO2 indicator.