Ecological Factors Influencing <I>Aedes aegypti</I> (Diptera: Culicidae) Productivity in Artificial Containers in Salinas, Puerto Rico

Abstract

We investigated the effects of environmental factors and immature density on the productivity of Aedes aegypti (L.) and explored the hypothesis that immature populations were under nutritional stress. In total, 1,367 containers with water in 624 premises were studied in Salinas, southern Puerto Rico (May-July 2004). We counted 3,632 pupae, and most female pupae (70%) were in five of 18 types of containers. These containers were unattended and influenced by local yards' environmental conditions. Pupal productivity was significantly associated with the number of trees per premise, water volume, and lower water temperatures. Larval and pupal abundance were larger in containers with leaf litter or algae. Pupal productivity and biomass of emerging females varied in containers with litter of different tree species. We found a significant and positive association between numbers of larvae and pupae of Ae. aegypti and a negative relationship between larval density and mass of emerging females. From multivariate analyses, we interpreted that 1) food limitation or competition existed in a number of containers; and 2) to a lesser extent, there was lack of negative larval density effects in containers with a larger water volume and lower temperature, where emerging females were not under nutritional stress. Corroborating evidence for food limitation or intraspecific competition effects came from our observations that females emerging in the field had an average body mass comparable with those females produced in the laboratory with the lowest feeding regime. Ae. aegypti larvae in Salinas are most likely influenced by resource limitation or competition and by rainfall in unmanaged containers in the absence of aquatic predators. Source reduction and improved yard management targeting unattended containers would eliminate most Ae. aegypti productivity and removal or control of shaded, larger containers would eliminate the production of the largest emerging mosquito females in the study area.

Tire-breeding mosquitoes of public health importance along an urbanisation gradient in Buenos Aires, Argentina

“…A similar trend was previously reported in flower vases within the study area (Vezzani & Albicócco 2009) and there is general consensus that there are higher frequencies of containers harbouring Ae. aegypti in shaded habitats (e.g., Focks et al 1981, Kittayapong & Strickman 1993, Vezzani et al 2005, Barrera et al 2006). This trend was consistent along the three urbanisation levels, but statistical comparisons suggest that it was less marked within small localities.…”

Eco-bio-social determinants of dengue vector breeding: a multicountry study in urban and periurban Asia

“…26,34,35 They therefore require special attention by control services. Such containers were particularly accessible to vectors, as shown in our study by an increased PHI, where buildings were widely separated from each other, particularly by shaded areas.…”

Abbreviations and acronyms

“…Container capacity, water temperature, source of water and container location, all of which can vary seasonally (Strickman and Kittayapong, 2002;Lenhart et al, 2006;Koenraadt et al, 2008), have been cited as important ecological factors affecting the production of adult Ae. aegypti (Morrison et al, 2004;Barrera, Amador and Clark, 2006a). Access to humans for blood feeding is additionally important for the production of Ae.…”