| Background: Rats, mosquitoes, flies, and cockroaches are the main vectors in China. By the means of biting, pollution food, destroying instrument, and spreading disease, etc., they bring great harm to human health and daily life. Currently, chemical prevention and control is the main means of control vectors, however, the long-term and huge mass of using chemical pesticides results in different levels of vectors resistance, which has become the key factor to restrict the development of prevent and control vectors. The mastery of the basic fauna and its geographical distribution and resistance is the first and foremost prerequisite in vectors controlling. Cockroaches have the well-adjusted and fast-breeding characters. Their harm to human being has been becoming daily increasing, and the cockroaches have already been one of the hardest prevention and control vectors.Objective: 1. To know population structure distribution and density situation the main vectors in Longgang district of Shenzhen, China. to offer scientific basis for the design of controlling vectors.2. To investigate the resistance of dominant species and provide a scientific basis for the use of insecticides. To explore if the feasibility of the biological chemical indices can be used as index surveillance. Methods: 1. The surveillance of main vectors population and density: Multi-method was employed in this study. Trap-night method was used for the surveillance of rats; At the same time, the rat taping- cage approach was used to combine the trap-night method to monitor the rat density at the investigated zones; ultraviolet lamp baited trap method; mosq-ovitrap and small containers method for mosquitoes;paste catching method for cockroaches and flies. 2. Chemical resistance of Blattella Germanica surveillance: The jar method of insecticide exposure was used to German cockroach. the GSTs,AKP,ACP,ATP,SOD,AChE activities was detected by GSTs AKP,ACP,ATP,SOD,AChE kit to compare the natural strains with susceptible strains.Results: 1. Study shows that, totally 35 rodents were captured. Rattus norvegicus is the dominant rodent at populated, the average density of rodents is 3.95%; according to statistics processing, the difference of the rodents density of the main streets in Longgang has statistical significance. Rodents densities of special industries, and residential areas had no statistical significance, Comparison of trap-night and cage-night methods shows that rat densities of both methods had no statistical significance. 1149 mosquitoes were captured in 2009, the annual average mosquitoes density is 1.48 individual in a lamp per hour. Culex pipiens Quinquefasciatus is the dominant specie of mosquitoes, account for 71.28%, following is Anopheles Sinensis, account for 16.28%. respectively. according to statistics processing, the difference of the mosquitoes density of the main streets in Longgang has no statistical significance. The mosquitoes in the hospital distribute more than in parks and resident communities. Average annual ovitrap positive rate is 6.95%, six street ovitrap positive rates show no statistical significance. The difference of the ovitrap positive rate by the ovitrap monitored in the environments of communities, construction site, hospital and park has no statistical significance.Total breteau index of Longgang is 50.68, All investigation streets breteau indices are all over 20. 570 flies were captured, the dominant specie of flies is Musca Domestica, accounting for 81.93% with the average density of 0.91 individual per strip. the difference of the flies density of the main streets in Longgang has no statistical significance. Blattella Germanica is the dominant specie of cockroaches with 96.62%, Blattella Germanica distributions in the restaurant industry, hotel, and community have a statistically significant differences. the difference of the cockroaches density of the main streets in Longgang has no statistical significance 2. Blattella Germanica belongs to high resistance level to synthetic pyrethroid insecticides and carbamate insecticide, except Baygon. Inhibition of GSTs,ACP,AChE in Blattella Germanica between natural strains with susceptible strains has a statistically significant differenceConclusion: The vectors density in Longgang district is relatively high, rodents and mosquitoes densities are far beyond the national standards, especially the Breteau Index, the risk of the occurrence of disease dengue fever is relatively higher in this district. Mosquitoes,rodents,flies and cockroaches should be controlled all round the year.The experimental tests showed that cockroaches have reached high resistance to insecticides. The integrated control strategy should be suitable, and reasonable use of insecticides is needed. The activity of GSTs,ACP,AChE in Blattella germanicamay can be used as one of the indices for determining resistant level to insecticides. |
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