The role of detritus type in competition and distribution of container-dwelling Aedes

Aedes aegypti and Aedes albopictus are invasive mosquitoes inhabiting artificial containers as larvae.  Field and lab studies show that A. albopictus is the superior competitor when the larvae co-occur; however, field surveys indicate that the two species have maintained apparently stable coexistence in some Florida cemeteries, whereas other cemeteries are populated by only A. aegypti or only A. albopictus.  Other studies have shown that larval survival and development may be affected by manipulating detritus types present in the water; different detritus types are thought to alter the abundance of microorganisms upon which mosquito larvae feed.  We conducted laboratory studies and field surveys to determine if variation in detritus types across Florida cemeteries may affect the pattern of coexistence/exclusion observed in these Aedes species.  In the laboratory, A. albopictus survival was not affected by interspecific competition, whereas the effect of interspecific competition on A. aegypti was significantly altered by detritus type.  In the laboratory, A. albopictus and A. aegypti larvae raised in water obtained from cemeteries of known Aedes composition had significantly faster development and greater survivorship in water from A. aegypti-dominant cemeteries than in water from A. albopictus-dominant cemeteries.  Detritus and water samples from Florida cemeteries show greater abundance of certain detritus types and suspended organic matter in vases from A aegypti-dominant cemeteries than in those from A. albopictus-dominant cemeteries.  These studies collectively indicate that differences in detritus type may affect food availability across sites, and may contribute the pattern of A. aegypti and A. albopictus distributions throughout Florida.