Larval habitat diversity and ecology of mosquito larvae (Diptera: Culicidae) in the Republic of Moldova

The main goal of the present study was to determine the impact of aquatic habitat diversity on mosquito species composition, density and spatial distribution in the Republic of Moldova. The surveys were carried out in 45 settlements throughout Moldova. Larval collections have been conducted between April and October in 2011 and 2012. Total of 164 larval habitats were surveyed: permanent large water bodies (n = 31), permanent ditches (n = 18), temporary rain pools (n = 43), hoof prints (n = 27), artificial containers (n = 21), flooded forest (n = 1) and tree holes (n = 23). Altogether 5763 larval specimens were collected and their identification revealed the presence of 14 species in 6 genera. Variation in larval densities among habitat types were analyzed using one-way analysis of variance (ANOVA) test. Larvae were sampled using standard dipping techniques (Silver, 2008). Larval densities were expressed as number of larvae per 1m² of the water surface. Culex pipiens (39.3% of all collected specimens) was the most abundant species in hoof prints (2145.4±873.2 larva/m²), rain pools (203.4±66.5 larva/m²) and artificial containers (139.6±55.3 larva/L³), followed by Anopheles maculipennis s.l. (32.1%) distributed in large water bodies (87.8% positive breeding sites with larval density 40,2±6,3 larva/m²) and abundant in permanent ditches (159.1±13.5 larva/m²) and hoof prints (133.2±74.0 larva/m²), Cx. modestus (10.6% of all collected specimens) was abundant in large water bodies (52.5±13.2 larva/m²), Dahliana geniculata (5.0%) was detected in tree holes (682,3±397,9 larva/L³) and Cx. torrentium (4.3%) mainly distributed in rain pools (411.2±151,9 larva/m²). Larvae of Ochlerotatus dorsalis (2.3%), Oc. caspius (1.4%), Cx. territans (1.2%), Ur. unguiculata (1.1%), Aedimorphus vexans (0.7%), Anopheles pseudopictus (0.09%) and An. plumbeus (0.05%) were less abundant. The Anopheles maculipennis complex, identified by rDNA PCR, using specific primers (Proft et. al., 1999), included three species An. melanoon (51.8% of all identified An. maculipennis s.l. larvae), An. messeae (42.4%) and An. atroparvus (5.8%). Water temperature had a significant effect on larval densities among the different habitats. The mean water temperature was variable among different larval habitats (P<0.001) and larval density was positively correlated to water temperature (R = 0.26; P<0.001).