Comparison of nocturnal activities of mosquitoes (Diptera: Culicidae) sampled by New Jersey light traps and CO2 traps in Belek, Turkey.

Temporal and seasonal variations in the nocturnal activities of adult females of six locally common mosquitoes, Aedes cretinus, Ochlerotatus caspius, Oc. dorsalis, Culex pipiens, Cx. tritaeniorhynchus and Culiseta annulata were studied at Belek, Turkey, using New Jersey light traps and CO2 charged olfactory traps. In addition to assessing the relative value of these traps as sampling devices capable of measuring activity at different periods of the night, these studies also examined the seasonal contribution of each species to the phenology of the overall mosquito population. While statistical results showed that differences in activation time preferences were found to be not significant for each species, the nocturnal activity profiles of Cx. tritaeniorhynchus, Ae. cretinus and Oc. caspius were definitely differed from those of other species. Ae. cretinus was a common species with a rate of 26.1% at 18:00-20:00, whereas the adult rate of Cx. tritaeniorhynchus was determined to be the lowest (11.4%) at that time interval. Significant differences were found at the time intervals 18:00-20:00, 22:00-24:00 and 02:00-04:00 in the general bias of mosquito populations among different months. While the nocturnal patterns of Cx. tritaeniorhynchus and Ae. cretinus were found to be bimodal, it was monomodal for Oc. caspius and Cu. annulata, unimodal for Cx. pipiens and Ae. dorsalis. While 69.6% of females captured by traps throughout the study period were found to be unfed, 24.8% were fed, 4.1% were half-gravid and 1.4% were gravid. Statistical results of trap preferences of Aedes species were found to be significant (P < 0.05). Oc. caspius and Ae. dorsalis preferred New Jersey light traps to CO2 traps. Light trap and CO2 trap collections can be influenced by design features including the amount of contrast between the light sources and surroundings. These features were found to be highly significant factors for the biting activity Cx. pipiens and Cx. tritaeniorhynchus.

Evaluation of protective efficacy of K-OTAB impregnated bednets for cutaneous leishmaniasis control in Southeast Anatolia-Turkey.

Large-scale field trials were performed in an endemic focus of cutaneous leishmaniasis in both urban and rural settlements of Sanliurfa City, SE Anatolia, Turkey, to evaluate the efficacy of insecticide impregnated bednets. An intervention field trial promoting the use of K-OTAB (deltamethrin-tablet formulation) impregnated bednets by the local inhabitants of five quarters for cutaneous leishmaniasis was performed between July 2000 and July 2001. The aim was to examine the monthly and annual efficacy of such bednets in controlling cutaneous leishmaniasis and to compare effect of impregnated bednets (IB) with non-impregnated bednets (NIB). Results showed significant (P < 0.05) reduction in cutaneous leishmaniasis incidence in the intervention areas from 1.87 % to 0.035% in Yenice and from 2.3% to 1.32% in Suruç B. In contrast, cutaneous leishmaniasis incidence increased in the untreated control areas from 1.03% to 1.38% in Suruç A. The annual incidence of the second control area for cutaneous leishmaniasis experiments showed almost no change at all(1.1% in July 2000; 1.02% in July 2001). Similar to results of control areas, cutaneous leishmaniasis incidence rates showed an increase despite the bednets in the Suruç C (1.22% to 1.47%) where NIBs were distributed.

Effect of insecticide-treated bednets for malaria control in Southeast Anatolia-Turkey.

Deltamethrin is one of the most effective insecticides for vector control, already widely used for bednet impregnation to control malaria. To evaluate the efficacy of deltamethrin-impregnated bednets in malaria control and in reducing the biting nuisance caused by Anopheles sacharovi, field trials were carried out in an endemic area of malaria in the surrounding rural settlements of Sanliurfa City, SE Anatolia, Turkey. Preliminary studies commenced in August 1999 with pre-intervention house-to-house surveys to identify villages outside of Sanliurfa City with high malaria incidence, to collect socio-economic, epidemiological and entomological data, and to determine physical properties of the study areas. An intervention field trial promoting the use of K-OTAB (deltamethrin-tablet formulation) impregnated bednets by local inhabitants of four villages was performed between July 2000 and July 2001. Its aim was to examine the monthly and annual efficacy of such bednets in controlling malaria and to compare the effect of impregnated bednets (IB) with non-impregnated bednets (NIB). The experimental design consisted of four villages. Gedik was selected as the intervention area using IBs, Orgulu served as the control area, and in Persiverek and Sandi NIBs were implemented. All 1,406 inhabitants of the 146 households were recruited for the study. Results showed significant (P < 0.05) reduction in malaria incidence in Gedik from 8.29% in the pre-treatment year to 1.57% in the post-treatment year. In contrast, malaria incidence slightly increased in Orgulu from 6.55% to 7.58%. Similar results were obtained from the other two villages where NIBs were used; malaria incidence rates increased from 2.16% to 6.77% (Persiverek) and from 1.9% to 9.8% (Sandi). Entomological surveys, employing different techniques, were carried out randomly at selected collection sites within the intervention and control settlements every month from June 2000 to June 2001 to determine the fluctuation of seasonal population sizes and compare the monthly density of malaria vectors between intervention and control areas.

Species composition and seasonal dynamics of mosquitoes in the Belek region of Turkey.

The species composition and seasonal population dynamics of mosquitoes trapped in the Belek Region of Turkey are described. Eight traps (four New Jersey light traps and four CO2 baited traps) were activated weekly at four different sampling sites (wooded area, open field, village, and road edge). Between May and December, 1997, 4,542 specimens representing seven species (Culex pipiens, Culex tritaeniorhynchus, Aedes caspius, Aedes cretinus, Aedes dorsalis, Aedes vexans, and Culiseta annulata) were collected. The most abundant species was Cx. pipiens (26.7% of total catch) followed by Cx. tritaeniorhynchus (23.8%), Ae. caspius (23.4%), Ae. cretinus (10.7%), Ae. dorsalis (8.7%), Cs. annulata (6.2%), and Ae. vexans (0.1%). This is the first record of Ae. cretinus in the area since 1984. The species was captured throughout the study period, although it was most abundant in late summer. Culex tritaeniorhynchus reached its highest density in August, while Cx. pipiens was found in high numbers throughout most of the study period.