中华按蚊对3种细菌的产卵反应

Oviposition responses of Anopheles sinensis (Diptera:Culicidae) to three bacteria

目的具吸引作用的细菌或其挥发物能提高按蚊与杀虫或抗疟工程细菌接触的机会,为此,拟测定中华按蚊对A4细菌(未鉴定)、气单胞菌和肠杆菌的产卵反应特性,以明确3种细菌对中华按蚊是否具有吸引特性,为应用这3种细菌开展阻断疟疾传播研究提供理论和实验依据。方法已交配雌按蚊吸饱血48～60h后,将含不同细菌的滤纸产卵器放入蚊笼中供按蚊产卵。保持黑暗12h,待按蚊产卵后计数产卵器中按蚊卵的数量,应用成对t检验法比较中华按蚊在不同处理的产卵器中产卵量的差异。结果中华按蚊在含肠杆菌产卵器中的产卵量最多,在含A4菌和气单胞菌的产卵器中的产卵量明显低于对照和含肠杆菌的产卵器中的产卵量,P值分别为0.026、0.012、0.048和0.016;含肠杆菌的产卵器中的按蚊卵数量略高于对照,但差异无统计学意义(P>0.05)。结论中华按蚊产卵时对A4菌和气单胞菌具有明显的负趋性,而对肠杆菌仅具有微弱的趋向性,推测这3种细菌可能不是中华按蚊食物的优先选择,但具有在蚊中肠内较为稳定存活的可能性,因此更适合于作为蚊幼生物杀虫基因的寄主细胞和仿转基因按蚊抗疟基因的寄主细胞被应用。

Objective To determine the oviposition responses of Anopheles sinensis to bacteria A4 （unidentified）,Aeromonas sp. and Enterobacter sp. and whether or not the three strains attracted the mosquitoes,providing theoretical and experimental evidence for the application of the three bacteria in the intervention of malaria. Methods Blood-fed and held for 48-60 h,copulated female An. sinensis were placed into cages with filter-paper oviposition cups that contained different bacteria in darkness for 12 h egg laying. The numbers of eggs in the oviposition cups counted,the difference was analyzed using paired t-test. Results Gravid An. sinensis laid the most eggs in the oviposition cups containing Enterobacter sp. The numbers in those containing bacteria A4 and Aeromonas sp. were significantly lower than those in the control cups and those containing Enterobacter sp.,with the P values of 0.026,0.012,0.048 and 0.016,respectively. Despite slightly greater number of eggs in the oviposition cups of Enterobacter sp. compared to the control group,there was no noticeable difference between the two （P〉0.05）. Conclusion Gravid An. sinensis demonstrated significant negative taxis towards bacteria A4 and Aeromonas sp.,as well as slight taxis to Enterobacter sp.,implying that the three bacteria were not the dietary preference for An. sinensis. However,in light of the possibility of their stable colonization into mosquito＇s guts,these strains may serve as the host cells of larvicide genes and transgenic anopheline antimalarial genes.