CONICET | Buscador de Institutos y Recursos Humanos

In Argentina, despite local Aedes albopictus presents a certaindegree of egg dormancy that would allow to be present attemperate latitudes its distribution is limited to two provinces witha subtropical climate: Misiones and Corrientes. Therefore, it ispossible that other factors are limiting the expansion of thisvector. To evaluate possible interactions that are affectingpopulation and spread of this specie, we sampled artificialbreeding site in Eldorado (urban environment) and ColoniaAurora (rural environment), Misiones province, in October 2015,April and November 2016 and April 2017. We performedgeneralized linear mixed models to evaluate which variables(type of container, volume of water, and environment) areassociated with the presence of Ae. albopictus, Ae. aegypti, andmosquito predators (Lutzia bigoti and Toxorhynchites spp.). Also,in each environment, relationship between Ae. albopictus and Ae.aegypti was quantified through Hurlbert's C8 associationcoefficient. In Eldorado we collected 17195 larvae from 258containers. Aedes aegypti was dominant (66.69%), while Culexquinquefasciatus represented 19.06% and Ae. albopictus 6.49%.In Colonia Aurora, of 5319 specimens collected from 149 artificialbreeding sites, Cx. quinquefasciatus was the most abundantspecies (38.50%), Ae. albopictus was the second most abundant(23.82%) and Ae. aegypti accounted 12.24%. The presence ofAe. albopictus was higher in the rural environment (probability:0.25±0.08) than in the urban environment (0.14±0.06) (χ2= 4.933;df=1; p= 0.026). It was also higher in containers with 1-10 liters(0.39±0.09) and 10-100l of water (0.42l±0.09) than breeding siteswith 0-1l (0.05±0.04) and >100l (0.10±0.06) (χ2= 19.228; df=3,p=2; 453e-4). The presence of Ae. aegypti was associated withthe environmnet (χ2= 36.196; df=1; p=1.784e-09). It was higherin the urban environment (0.96±0.02) than in the rural(0.38±0.08). The presence of predators was highest in the ruralenvironment (χ2= 4.048; df=1; p=0.044), reaching 29.03% of thebreeding sites in November 2016. Regarding C8 index, Ae.aegypti was negatively associated with Ae. albopictus inEldorado city (C8=-0.105) and in the rural municipality, thesespecies presented a positive relationship (C8=0.376). Theseresults show that in the urban environments the high abundanceof Ae. aegypti could be affecting the presence and abundance ofthe Asian tiger mosquito as evidenced by local studies of larvalcompetition. And, in the rural environment, although theabundance of Ae. albopictus is higher, its presence is lower thanthe presence of Ae. aegypti. Possibly, a higher presence ofpredators in the rural environment is also conditioning the Asiantiger mosquito.