Middle East DVEP - Armed Forces Pest Management Board

Culex pipiens pipiens occurs throughout the region. Culex univittatus is distributed in thecoastal plains of Kuwait, Iran, Iraq, Israel, Lebanon, Oman, Saudi Arabia, Syria, Turkey(coastal plains and central plateau) and Yemen. Culex pipiens molestus is found in thecoastal plains of Iran, Israel, Lebanon and Saudi Arabia. It may also occur in adjacentcountries. Culex perexiguus occurs in Iran, Iraq, Lebanon, and Turkey. Culexantennatus occurs in Iran, Israel, Saudi Arabia and Yemen.Culex pipiens molestus and Cx. p. pipiens usually prefer to feed on birds but readily feedon humans and large animals like camels, cattle and goats. They are annoying biters andproduce a high-pitched buzzing sound that can be easily heard. Members of the Cx.pipiens complex feed and rest indoors or outdoors. Three or 4 days after a bloodmeal,Culex pipiens deposits egg rafts containing 75 to 200 eggs on the water surface.However, Cx. p. molestus is autogenous and does not require a bloodmeal prior tooviposition. Common oviposition sites include cisterns, water troughs, irrigationspillovers, wastewater lagoons, and swamps. Eggs hatch 2 to 4 days after deposition.Larvae of the Cx. pipiens complex generally prefer ground pools with highconcentrations of organic matter or swamps with emergent vegetation. Polluted waterfrom septic systems is an ideal breeding site for the Cx. pipiens complex. Larvaldevelopment requires 7 to 9 days at a temperature range of 25 to 30°C. At lowertemperatures, larval stages may require 15 to 20 days. The pupal stage lasts about 2 days.Adult populations display two small population peaks in temperate countries, one fromMay to June, and another from September to October. However, since Cx. pipiens s.l.frequently breeds in various types of wastewater, the peaks are not as sharp as for otherCulex species. In the Arabian Peninsula, populations of this mosquito occur year-roundbecause wastewater is freely available most of the year. Increasing urbanization and poorsewage systems in many parts of the Middle East contribute to the spread and abundanceof Cx. pipiens.Culex univittatus breeds in swamps, slow-moving streams, or ground pools with eitherhigh organic content or dense vegetation. The life cycle is similar to that of the Cx.pipiens complex. Although Cx. univittatus tolerates organic matter, it prefers relativelyclean water compared to the Cx. pipiens complex and is much more dependent on rainfallin order to propagate in large numbers. Culex univittatus also prefers birds but bites manreadily during its peak population periods. In contrast to the Cx. pipiens complex, Cx.univittatus is less likely to feed indoors.Culex perexiguus breeds in standing ground pools, irrigation plots, date palm plots, andrice fields, particularly in Iran. It prefers breeding sites with vegetation and sunlight.Culex antennatus breeds in sunlit, grassy ponds with relatively clear, clean water. Ricefields and isolated stream pools are the most common habitats reported for this species inthe Middle East. Culex antennatus and Cx. perexiguus feed and rest primarily outdoors.All these Culex species generally begin biting at dusk and continue throughout the night,with peak biting occurring the first hours after sunset.In temperate countries, Culex univittatus, Cx. antennatus, and Cx. perexiguus have twopronounced population peaks: one occurring from May to June, and a second occurring103