Functional groups of insects and habitat characteristics in lenctic water bodies in Cordoba, Argentina

HERRERO, M.A.; PIRES, D.A.; GLEISER, R.M.

San Juan

Congreso; 2da Reunión Conjunta de las Sociedades de Biología de la República Argentina.; 2011

Environmental modifications due to urbanization, such as vegetation removal, soil compaction and impermeabilization, septic water management, may affect the presence of insect fauna and predator colonization in urban water bodies. There are few studies assessing insect communities in Argentine urban lentic bodies that are potential larval habitat of disease vectors such as mosquitoes. Relations between presence of aquatic insect functional groups and water body characteristics were explored in Córdoba city. Entomological samples were collected weekly (December 2009 to March 2010) in 17 water bodies (ditches, ponds, canals), and their environmental characteristics were recorded (plant type and cover, substrate, temperature, pH, depth, etc.). Specimens were fixed and stored in 80% ethanol, counted, identified and assigned to one of 4 functional groups based on their prevailing adaptations for food acquisition (generalists, collectors, scrapers, predators). Out of 12,900 specimens, 98.1% were Diptera (mostly mosquitoes), 1.3% Odonata, 0.3% Heteroptera and 0.3% Coleoptera. Correspondence analysis showed that the presence of predators was related to flooded grasses and weeds, while generalists and collectors were related to emergent plants. Scrapers and predators (except Libellulidae) were associated with intermittent water (<15days of water permanence), while generalists were associated with longer permanence water. Collectors, Chironomidae and Stratiomyidae were associated with intermittent water bodies, Psychodidae and Syrphidae with permanent water and Culicidae did not show a clear pattern regarding water permanence. In conclusion, these results suggest that the presence of vegetation combined with intermittent water permanence sustain a higher aquatic insect diversity in lentic urban water bodies of Cordoba city.