Spatial Ecology of Aedes Albopictus in Suburban Landscapes of a Piedmont Community in North Carolina
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Date
2005-09-25
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Abstract
The objectives of our study were to investigate the spatial ecology of Ae. albopictus, to evaluate some potential management methods, and to characterize its host feeding patterns in a suburban landscape. We monitored Ae. albopictus oviposition activity with oviposition traps at fixed stations, conducted container surveys for larvae and pupae, and collected adults from vegetation at residences in eight suburban neighborhoods in Raleigh, NC during the 2002 and 2003 mosquito seasons. Host sources of blood fed mosquitoes were determined by an indirect Enzyme Linked Immunosorbent Assay, using antisera made in New Zealand white rabbits to the blood serum proteins of humans and, domestic and wild animals.
An area-wide management strategy involving a lethal oviposition trap (LOT) placed in the landscape around homes in suburban neighborhoods was evaluated. The trap consisted of a black plastic cup filled with water and containing an oviposition substrate impregnated with an insecticide. Source reduction (SR) of water-filled containers was also evaluated as a management strategy for Ae. albopictus in combination with the LOT and as a stand-alone area-wide approach to control. Analysis of variance did not reveal any significant mosquito suppression (P > 0.05) resulting from the LOT, SR, or the combination of LOT and SR during the 2002 and 2003 mosquito seasons. We determined that the mosquito production potential of a container was a function of its pupal standing crop, density, and spatial distribution in the landscape. Spatial statistical methods were used to evaluate impacts of SR of man-made, water-holding containers on the spatial structure of the population of Aedes albopictus immatures. Spatial analyses considering the presence or absence of pupae revealed that residences with at least one pupa-positive container tended to be dispersed throughout SR areas and clustered throughout control areas, indicating that SR affected the spatial distribution of pupae. We used kriging to show the spatial distribution of oviposition activity within neighborhoods. Areas of high and low egg production existed in most neighborhoods; however, spatial patterns of oviposition changed between seasons. Oviposition activity peaked in late summer in both the 2002 and 2003 mosquito seasons. Aedes albopictus primarily fed on mammals, but took blood meals from 12 different hosts or host classes, including birds, frogs, and turtles. The largest proportion of blood meals was taken from humans, followed by cats and dogs. Host feeding indices were calculated for human and domestic animal hosts based on the proportion of host specific blood-fed mosquitoes per collection in relation to the number of corresponding specific hosts per residence established from a door-to-door host survey. When host abundance was considered solely, host-feeding indices indicated that Ae. albopictus was more likely to feed on domestic animals. When feeding indices included host abundance that was time-weighted based on potential exposure to mosquitoes, Ae. albopictus fed preferentially upon humans.
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Spatial distribution, mosquito
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Degree
PhD
Discipline
Entomology
