Ochlerotatus albifasciatus in Tierra del Fuego, Argentina, austral extreme of the Americas

BURRONI, NORA EDITH; LOETTI, MARÌA VERÓNICA; MARÍA CRISTINA MARINONE,; FREIRE, MARÍA GABRIELA; NICOLAS SCHWEIGMANN

Open Journal of Animal Sciences

Scientific Research Publishing Inc

Año: 2013 vol. 4 p. 5 - 10

2161-7597

The information about ecological topics of mosquitoes at the southernmost tip of South America is fragmentary and scarce. The present study evaluates lentic freshwater habitat located in the surroundings of main roads of the Argen- tine sector of Tierra del Fuego as larval habitat of Ochlerotatus albifasciatus, also analyzes the relationships between their presence and sev- eral environmental variables: water turbidity, per- centage of gramineans, percentage of macro- phytes, presence of crustaceous cyanobacteria, and filamentous chlorophyceans. Mosquito in- matures were collected with dip nets. A gener- alized linear model (GLM) with negative binomial error distribution was used to determine the ef- fects of different variables of the water bodies on abundance of Oc. albifasciatus in the larval habitats. Collections were made in 45 lentic freshwater bodies. Preimaginal stages were found in 17.70% of the studied habitats. Oc. albifasciatus was the only culicid registered. The GLM explained 93.17% of the variability, and showed a negative relationship between the abundances of Oc. albifasciatus and water tur- bidity, and a positive relationship with percent-age of gramineans. The gramineans would im- prove food supply, because the plants are pro- viding suitable substrate for different types of microbiota, a layer of leaves would protect eggs from extreme temperatures, and could help the larvae to hide from potential predators. The negative association between abundance of this species with water turbidity could be related to the presence of vegetation that favors retaining the substrate, reducing water turbidity. Ochlerotatus albifasciatus, also analyzes the relationships between their presence and sev- eral environmental variables: water turbidity, per- centage of gramineans, percentage of macro- phytes, presence of crustaceous cyanobacteria, and filamentous chlorophyceans. Mosquito in- matures were collected with dip nets. A gener- alized linear model (GLM) with negative binomial error distribution was used to determine the ef- fects of different variables of the water bodies on abundance of Oc. albifasciatus in the larval habitats. Collections were made in 45 lentic freshwater bodies. Preimaginal stages were found in 17.70% of the studied habitats. Oc. albifasciatus was the only culicid registered. The GLM explained 93.17% of the variability, and showed a negative relationship between the abundances of Oc. albifasciatus and water tur- bidity, and a positive relationship with percent-age of gramineans. The gramineans would im- prove food supply, because the plants are pro- viding suitable substrate for different types of microbiota, a layer of leaves would protect eggs from extreme temperatures, and could help the larvae to hide from potential predators. The negative association between abundance of this species with water turbidity could be related to the presence of vegetation that favors retaining the substrate, reducing water turbidity.