Anopheles species and their relation to land covers in ...

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... Coberturas de la Tierra. Metodología. CORINE Land Cover adaptada para Colombia Escala 1:100.000. Primera edición. Bogotá D. C. Editorial Scripto Ltda; ...
Anopheles species and their relation to land covers in a malaria endemic region of Colombia Juan C. Hernández-Valencia1, Daniel S Rincón1, Juan D. Sánchez1 , Stiven Quintero1, Nelson Naranjo-Díaz1, Alba L. Marín Valencia2, Margarita M. Correa1 1. Grupo de Microbiología Molecular, Escuela de Microbiología, Universidad de Antioquia 2. Departamento de Ingeniería Sanitaria y Ambiental, UdeA

MATERIALS AND METHODS B

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INTRODUCTION Land cover strongly influences the composition and diversity of the Anopheles mosquito community [1-3]. This work explored the relation between land cover and Anopheles composition and diversity in five localities highly influenced by human transformation, from an important endemic malaria region of Colombia.

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Species Region Bajo Cauca Locality Puerto Astilla Cuturu Puerto Triana La Lucha Villa Grande

Figure 1. Localities and municipalities of study in the Bajo Cauca region. A) Colombia, B) Antioquia, C) Bajo Cauca

La Lucha

Villa Grande

Cuturu

Puerto Triana

Puerto Astilla

Figure 2. Species richness (x axis) and abundance (y axis), by locality.

2,458 Anopheles mosquitoes corresponding to 10 species were collected in five localities during 180 hours of sampling. Anopheles braziliensis (n = 874, 35.6%) Anopheles nuneztovari (n = 581, 23.6%) and Anopheles darlingi (n = 495, 20.1%) were the most abundant species (Fig 2).

Collection and species identification • • • • • •

Field trips: 2013-2014 Three municipalities, five localities (Fig 1). Six sampling sites per locality From 18:00 to 24:00h (Human landing catches, animal and resting) Indoors and outdoors Morphological identification and molecular confirmation [4, 5].

Land cover classification • Digitalization in ArcGIS – ESRI. Area of 1.5Km radio using Orthophotos with scale 1:10.000. • Classification according to the National Legend of land cover– IDEAM [6]. • Estimation of landscape metrics. Software: V-LATE

Figure 3. Land cover maps for the five study localities

Analysis ● Shannon index (measure of diversity) ● Spearman's rank correlation coefficient (correlation between species and land covers) ● Canonical correspondence analisis (CCA) (relation between species and land covers).

RESULTS Seven cover types were observed: forest, shrub, grass, crop, bare soil, water bodies and wetland (Table 1, Fig 3). The forest was the defined matrix for La Lucha and Villa Grande. Cuturú, Puerto Triana and Puerto Astilla presented landscapes without a defined matrix, product of the fragmentation caused by mining activity that takes place in these locations (Fig 3). Table 1. Land covers area (Ha) and landscape diversity* per municipality and locality. El Bagre Caucasia Nechí La Lucha Villa Grande Cuturú Puerto Triana Puerto Astilla Land Cover 906 688 97 328 169 Forest 329 264 142 207 186 shrub 142 186 360 620 47 Grass 1 4 Crops 37 62 227 45 208 Bare soil 10 37 194 10 111 Water bodies 111 191 314 Wetlands 0.988 1.203 1.688 1.416 1.67 Shannon index*

ACKNOWLEDGMENTS • •

All members of the group of Molecular Microbiology at the University of Antioquia. This study received support from Estrategia para la Sostenibilidad de Grupos de Investigacion 2016-2017, Universidad de Antioquia, and COLCIENCIAS, Project code No. 596-2013. M.A. and N.N. received financial support for their PhD studies from COLCIENCIAS.

Figure 4. CCA for the abundances of the Anopheles species in relation to land cover.

According to the CCA, the An. darlingi abundance was found highly related to wetland, pasture and crop covers, An. nuneztovari exhibited a high relation with forest and shrub. Anopheles albitarsis was related to grass and wetland. An. braziliensis was related to water bodies, bare soil and wetland covers. Finally, Anopheles triannulatus presented a high relation with crop and pasture coverages. CONCLUSION • In most localities, the malaria vectors An. darlingi and An. nuneztovari showed the highest abundance, suggesting a high malaria transmission risk in these localities. • Together, these association results indicate that the presence and abundance of anopheline species are favored by the increase of anthropic activities that modify land cover. • The study of the relationship between Anopheles and the structure of the landscape can be useful to predict scenarios in which the presence of a species can be favored; this is useful for the implementation of malaria vector control, through the generation of unfavorable landscapes for Anopheles species of medical importance. REFERENCES 1. 2. 3. 4. 5. 6.

Acevedo MA, Prosper O, Lopiano K, Ruktanonchai N, Caughlin TT, Martcheva, M, Osenberg CW, Smith, DL. Spatial Heterogeneity, Host Movement and Mosquito-Borne Disease Transmission. Plos One 2015; 10(6). Dunning JB, Danielson BJ, and Pulliam HR. Ecological processes that affect populations in complex landscapes. Oikos 1992; 65: 169–175. Ulrich Walz. Landscape Structure, Landscape Metrics and Biodiversity. Living Reviews in Landscape Research. Leibniz Institute of Ecological Urban and Regional Development. 2011:5 González R, Carrejo NS. Introducción al estudio taxonómico de Anopheles de Colombia.. Universidad del Valle, Cali-Colombia. 2009; 2. p.260 Cienfuegos AV, Rosero DA, Naranjo N, Luckhart S, Conn JE, Correa MM. Evaluation of a PCR-RFLP- ITS2 assay for discrimination of Anopheles species in northern and western Colombia. Acta Tropica 2011; 118:2. pp128-135. IDEAM- Instituto de Hidrología, Meteorología y Estudios Ambientales. Leyenda Nacional de Coberturas de la Tierra. Metodología CORINE Land Cover adaptada para Colombia Escala 1:100.000. Primera edición. Bogotá D. C. Editorial Scripto Ltda; 2010. 72p.