Study On The Attractive Components Of Sugar-feeding Plants To The Adult Culex Pipiens Pallens

Mosquito is one kind of international sanitary pest, and it is labelled "the four pests" in China, because it can transmit malaria, Japanese encephalitis, dengue fever, etc. Now, synthetic chemical insecticides still play an important role in the mosquito control. However, indiscriminate uses of insecticides not only pollute the environment and disturb ecological balance, but also mosquitoes rapidly evolve resistance. Therefore, discovery of efficient and environmentally safe mosquito control technologies would be an important research subject.In this paper, we researched the sugar-feeding behavior of Culex pipiens pallens and wanted to find efficient mosquito-specific bait First, we investigated the wild sugar-feeding plants. Second, we analyzed the volatiles of some sugar-feeding plants. Last, we measured the attractiveness of volatile compounds from sugar-feeding plants.Major research results are as follows:(1) We selected three colors (Red, Yellow and White) and three shapes (Lily-shaped, Rose-shaped and Gypsophila-shaped) of common flowers to study the sugar-feeding behavior of adult C. pipiens pallens in response to different colors and shapes in the dark condition. The results indicated that colors and shapes treatments had no clear attractive or repellent action to the sugar-feeding behavior of adult C. pipiens pallens. That means the volatiles of sugar-feeding plants are the mainly factor to the sugar-feeding behavior of adult C. pipiens pallens in the dark condition.(2) In order to investigate the wild sugar-feeding plants. We tested the attraction of25flowers and5fruits, which were picked from Zijingang campus of Zhejiang University, to adult C. pipiens pallens in the laboratory. The results indicated that Nerium oleander, Abelia chinensis and Ligustrum quihoui were flowers with better attractiveness, and Broussonetia papyrifera and Cucumis melo were fruit with better attractiveness. The best attractiveness plant was Broussonetia papyrifera. There was a difference between field and laboratory experiment in the ratio of male mosquitoes to female mosquitoes. In the laboratory, the majority of flowers attract females more than males, but in the field, the number of males attracted by this sugar-feeding plant was two times more than females. The reason remains need to be further research.(3) The volatiles were identified by GC-MS from four flowering plants, which two of them had strong attractiveness and the other had no attractiveness. Pinene, ocimene, myrcene, limonene, phellandrene etc. existed in all of four plants. Benzaldehyde was only detected in Abelia chinensis, and1-Octen-3-ol was detected in Broussonetia papyri/era.(4) The attractive and repellent actions of ocimene, α-pinene, P-pinene,1-octen-3-ol, benzaldehyde, caproaldehyde and limonene against the male adults of C. pipiens pallens were tested by Y-type olfactometer. The results indicated that among the seven compounds tested, compared with control, the lower concentration (O.lul/g) benzaldehyde and caproaldehyde and0.01ul/g1-octen-3-ol attracted significantly (P＜0.01) to the male adults of C. pipiens pallens. But the higher concentration (1.0ul/g) limonene and a-pinene had significant (P＜0.01) repellent action to the male adults, in contrast to the control.