Effects Of Seasonal Climatic Variation On The Biological Characteristics Of Aedes Albopictus In Guangzhou

Objective:to explore the effects of seasonal climatic variation on the biological characteristics of Aedes albopictus in guangzhou,in order to provide theoretical and data support for the prediction of mosquito-borne diseases using climate models,and to provide basic data for the prevention and control of mosquito-borne diseases.Methods:In order to explore the influence of climate change on the biological characteristics of Aedes albopictus,BG-Sentinel trap(BG-trap)was used to investigate the population structure of common mosquito species from different habitats in Guangzhou,and to understand the density fluctuation of Aedes albopictus populationfrom different habitats in Guangzhou.SPSS 22.0 software was used for linear correlation and regression analysis to determine the relationship between population density of Aedes albopictus and temperature and precipitation respectively.Using 16S rDNA,wAlbA and wAlbB genotypes of wsp genesequence of Wolbachia,a PCR detection method was established to detect Wobachia infection of different species of mosquitoes from different habitats in Guangzhou.Meanwhile,Mega 6.06 software was used for phylogenetic analysis of the obtained gene sequence.The effects of different seasons on the growth,development,survival and reproduction of Aedes albopictus under simulated field conditions were determined by using the method of life table experiment.Results:We used BG-trap to collect a total of 6853 mosquitoes of 4 genera and 4 species(subspecies)from three different habitats,including 1028 Aedes albopictus,534 females of Aedes albopictus.Linear correlation and regression were used to analyze the influence of temperature and precipitation on the population of Aedes albopictus respectively.It was found that the density(y)of Aedes albopictus adult in the current month was correlated with the monthly average temperature(X1)in the previous two months,and the regression equation was y=-3.577+0.277X1.The density(y)of Aedes albopictus adult in the current month was correlated with the precipitation(X2)in the previous month,and the regression equation was y=0.689+0.016X2.A total of 4 common mosquitoes of 3 different habitats in Guangzhou were detected.Using the PCR amplification of 16S rDNA gene to detect Wolbachia,the positive rate of Aedes albopictus from the residential district was 100%,and that of Culex quinquefasciatus from the park was also 100%.The positive rate of nucleic acid detection of Wolbachia of 4 different mosquito populations was 50%?100%.There are three cases of wsp gene detection,only wAlbA genotype or only wAlbB genotype was detected,or the two genotypes of wAlbA and wAlbB were detected simultaneously.The 16S rDNA gene sequence of 14 mosquitoes infected with Wolbachia was obtained by PCR amplification,with a length of 441 bp.The wAlbA gene sequence of 14 mosquitoes infected with Wolbachia was 351bp.The wAlbB gene sequence of 12 mosquitoes infected with Wolbachia was 481bp.Phylogenetic analysis showed that wolbachia genotypes of different mosquito species from different habitats were different.The results of life table experiment showed that compared with laboratory conditions,the egg hatching rate of Aedes albopictus under the simulated field conditions was low,and the egg hatching rate decreased with the decrease of temperature.Under the simulated field conditions,the average development time of larvae is long,the pupation rate was similar to the laboratory conditions.Under the simulated field conditions,the average survival time of adult mosquitoes is long,and female mosquitoes have low average egg production.When the temperature as low as 12.3?,the Aedes albopictus larva can develop into adult.When the temperature is 16.3 ?,the Aedes albopictus adult can live for 30.0 days and lay eggs.Conclusions:There was no statistically significant difference in the total average density of Aedes albopictus in the three habitats of campus,community and park in Guangzhou,but there was a correlation between the density of adult Aedes albopictus in the current month and the average temperature in the previous two months and the precipitation in the previous month.The detection of wolbachia in natural Aedes albopictus,Culex quinquefasciatus and Armigeres obturbans from the three habitats,these different mosquito species were commonly infected by wolbachia bacterium,there were single infections of wAlbA or wAlbB,and there were co-infections of wAlbA and wAlbB.There were differences in Wolbachia genotypes among different mosquito species in different habitats in Guangzhou.Under low temperatures,Aedes albopictus larvae could develop and emerge and adults could survive and produce eggs.The major impact of changes in ambient temperature,relative humidity,and light intensity was on egg hatch rates,adult survivor time,and egg mass production,rather than on pupation or adult emergence rates.