Željko Zahirović

Seasonal dynamics of mosquitoes (Diptera: Culicidae) in Osijek (Croatia) for the period 1995-2004.

The ten year research (1995–2004) of adult mosquitoes in the area of Osijek by dry ice baited CDC traps has provided significant information on mosquito species, species prevalence, their dynamics and seasonal activity. A total of 207,136 adult mosquitoes comprising twenty species belonging to the following genera: Anopheles, Ochlerotatus, Aedes, Culex, Coquillettidia, Culiseta and Uranotaenia were collected. The seven most common species collected during this study were: Aedes vexans (75.6%), Ochlerotatus sticticus (13.3%), Culex pipiens complex (5.9%), Anopheles maculipennis complex (1.9%), Oc. cantans (0.9%), Oc. caspius (0.6%) and Oc. excrucians (0.6%). The temporal changes in the relative abundance of the twenty mosquito species in the Osijek area were reflected in three peaks: in May, July and September. Seasonal population dynamics differed between years and between mosquito species in relation to wetland, urban and forest habitats and was influenced by water level of the Drava and the Danube rivers.

Efficacy of mosquito attractants in various habitats of a floodplain

Efficacy of different mosquito attractants was invesigated at four sites in three plant communities (Galio-Salicetum albae, Populetum nigro-albae, Genisto elatae-Quercetum roboris) of flooded and forest habitats in Kopački rit Nature Park, Croatia. The attractants were: dry ice, horse urine, horse urine + acetone, acetone, 1-octen-3-ol and ammonium hydroxide baited CDC traps. A total of 11,441 mosquito specimens of 12 species were collected. Aedes vexans (91.43%) was the most numerous species. A statistically significant difference between the efficacy of dry ice and the other attractants was shown, whereas there was no difference between the other attractants. A greater number of specimens and species number were noted in the flooded plant communities (Populetum nigro-albae). The response of Ae. vexans to dry ice was higher in flooded sites, and it was significantly lower in forest habitat (Genisto elatae-Quercetum roboris) according to fuzzy c-means cluster analysis. The same analysis shows a higher efficacy of other attractants (horse urine, horse urine + acetone, acetone, octenol and ammonium hydroxide) in forest habitat when compared to the flooded area habitats.