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Mosquitoes of the genus Culex comprise important vectors of pathogenic arboviruses in our region, including West Nile and Rift Valley Fever viruses. To improve our understanding of the epidemiology and transmission dynamics of arboviruses, we need to study the behavior and ecology of their vectors. The feeding patterns of the vector mosquitoes can be very useful in determining how and where to focus control efforts. For example, determining the preferred blood hosts of the females can assist in the implementation of potentially efficacious strategies for focused control of mosquito females. Determining the plants from which both sexes derive their sugar meals can comprise the initial step towards the formulation of efficient lures for trapping mosquitoes. In the past, plant meal identification was based mainly on chemical detection of fructose and microscopical observations of cellulose particles in mosquito guts. More recent studies have utilized DNA barcoding capable of identifying plant food sources. In the current study, we identify multiple plant species from which large numbers of mosquitoes obtained their sugar meals in one experimental procedure. We employed next generation DNA sequencing to sequence the chloroplast specific plant genes atpB and rbcL.

Monitoring sand flies in the cutaneous leishmaniasis foci Kfar Adummim and Ma'ale Adummim from May to October generally yielded several hundred specimens per CO(2) baited trap. In the summer of 2009, a sharp rise in the number of sand flies trapped was recorded in Kfar Adummim, while numbers were similar to previous years in Ma'ale Adummim; approximately 4,000 specimens compared to about 400, with maximal catches of about 16,500 specimens in Kfar Adummim. We postulate that the sharp increase in sand fly numbers is directly related to the intensive construction conducted which enhanced sand fly breeding habitats., (© 2011 The Society for Vector Ecology.)

The OFF! Clip-On fan vaporizer device releasing metofluthrin was evaluated against phletobomine sand flies in the Judean Desert, Israel, in October, 2009. A total of 76,400 sand flies was collected, with male flies representing 98.3%Phlebotomus sergenti and 1.7%P. papatasi. Females comprised 43.0% of the total catch and included 6.7% blood-fed females. Similar proportions of flies were collected in both suction and sticky traps. In trials with unbaited suction traps, similar numbers of sand flies were collected in traps with a metofluthrin device, blank device, or no device (i.e., suction only). In suction traps baited with CO(2) , higher numbers of P. sergenti males and blood-fed females were collected in traps with a blank device compared to traps with a metofluthrin device. In sticky traps baited with CO(2) , there were no significant differences between catches in traps with a metofluthrin device, blank device, or no device. The results suggest metofluthrin from the device is not repellent against sand flies in a field environment despite showing insecticidal activity against flies collected in suction traps., (© 2011 The Society for Vector Ecology.)

The customary method for controlling leishmaniasis and sand fly bites in Israel is the spraying of large quantities of residual insecticides on walls of houses and neighboring surfaces. However, the high summer temperatures, strong radiation, and dust limit the efficacy of the method. The sand fly vectors of Leishmania appeared to come uphill to the village of Kfar Adumim. Therefore, to block their path and improve control, beta-cyfluthrine or DDT were repeatedly sprayed on a strip of cloth that was stretched on the ground along and near the peripheral houses. The efficacy of the treatments was examined by comparing the proportions of sand flies that had been caught before and after the treatments, below and above the belt. The capture near the houses of sand flies that had been marked by colored sugar baits below the protective belt indicated that they were moving uphill and crossing the strip. The catches showed a gradual uphill decrease, up to the houses, in the number of sand flies. However, the proportions of sand flies caught in the different sites were similar before and after insecticide treatments showing that the belt was ineffective. Laboratory tests of pieces of the sprayed strip and exposure of sand flies to similar pieces indicated that the lack of effect was not caused by deficiency of insecticides.

Resistance to insecticides of larval Culex pipiens populations in Israel has been monitored for ten years and the results were used for control planning. The insecticides tested were the organophosphates chlorpyrifos, fenthion, and temephos and the pyrethroids permethrin and cypermethrin. Over the years the relative resistance (R/R) values to chlorpyrifos in most populations tested were between 200-400, with records of up to 700 R/R. Practically no susceptible populations were found and the compound has been withdrawn from use, resulting in a decrease in the relative resistance values. In 1996 when fenthion was reintroduced, no resistant populations were found, but in the following years significant resistance appeared in an increasing number of populations with values lower than recorded for chlorpyrifos but still high (up to 100 R/R). All populations tested were found to be susceptible to temephos and accordingly the compound was reintroduced in 2002. Over the ten years, no significant resistance to cypermethrin was found in the majority of the populations tested, while a trend of increased resistance to permethrin was noted with a few records of >1000 R/R. The results demonstrate the importance of continuous monitoring of insecticide resistance for efficient mosquito control. Alternative insecticides and methods of control are discussed.