Observations on the Ecology and Behavior of Macroseius biscutatus, an Obligate Pitcher Plant Mite

Abstract

The current conservation status of arthropods symbiotically associated with tall-form Sarracenia spp. is poorly known. Yet these unique organisms and their associations are disappearing due to habitat loss, degradation and fragmentation. A survey was conducted of several genera of pitcher inhabitants from several sites in Alabama and Florida. The results of this survey indicate the possible extirpation of Exyra semicrocea from small, heavily managed sites, and that the presence of Exyra larvae is negatively associated with mite presence although dipteran associates are positively correlated with mites. Furthermore, I present experimental evidence that provides a possible explanation for the continued survival of Macroseius biscutatus, a pitcher plant dwelling acarid mite, in habitats where other pitcher inhabitants may have been extirpated. My experiments indicate that Macroseius biscutatus responds to cues indicating fire (i.e. smoke). Increased mite movement, including pitcher exit, at the time of fire may allow mites to locate refugia. In conclusion, while intense fire management in small wetland remnants seems to negatively impact E. semicrocea, these fires do not seem to affect M. biscutatus.