Influence of the aquatic plant, Lemna minor on the development and survival of Culex pipiens mosquito immature.

Many environmental factors, biotic and abiotic interact to influence organismal development. Aquatic plants are considered as important environmental factors. Duckweed considered plants and grasses aquatic that most widely used water in the world for its ability to grow and reproduce greenery in aquatic habitats and various breeding sites of mosquitoes. Effect of the aquatic Lemna minor on the development and survival of Culex pipiens mosquito immature was investigated under laboratory conditions. Duckweed plants were used as low (15 plants/cm²), medium (25 plants/cm²) and high (35 plants/cm²) density on the surface of the water. The results showed the presence of aquatic plants duckweeds was affected larval development and survival of Culex pipiens, where they reach 11.4, 12 and 19 days of larval duration at non-plant, low and high plant density, respectively. Survival of larval and larval-adult stages of mosquito shortened as the plant density interval increased (%: 47.16±2.84 and 32.93±0.87) compared to the absence of plant (94.83±0.83 and 95.87±1.35). Analyses data indicated a high density mats of duckweed plant was marked inhibitory effect on mosquito breeding. The attractiveness of oviposition site for vector mosquitoes is dependent upon a number of physical and chemical factors. Cage tests in the laboratory indicated that the plant could be a suitable breeding place for gravid females especially at polluted sites (F= 19.705, P= 0.0001). The suggestion is made that the aquatic plant might be considered as a natural vector control measure in certain types of breeding places.