Wondwosen Betelehem, Hill Sharon R, Birgersson Göran, Seyoum Emiru, Tekie Habte, Ignell Rickard
Department of Zoological Sciences, Addis Ababa University, Box 1176, Addis Ababa, Ethiopia.
Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 102, Sundsvägen 14, 230 53, Alnarp, Sweden.
Malar J. 2017 Jan 23;16(1):39. doi: 10.1186/s12936-016-1656-0.
Maize cultivation contributes to the prevalence of malaria mosquitoes and exacerbates malaria transmission in sub-Saharan Africa. The pollen from maize serves as an important larval food source for Anopheles mosquitoes, and females that are able to detect breeding sites where maize pollen is abundant may provide their offspring with selective advantages. Anopheles mosquitoes are hypothesized to locate, discriminate among, and select such sites using olfactory cues, and that synthetic volatile blends can mimic these olfactory-guided behaviours.
Two-port olfactometer and two-choice oviposition assays were used to assess the attraction and oviposition preference of gravid Anopheles arabiensis to the headspace of the pollen from two maize cultivars (BH-660 and ZM-521). Bioactive compounds were identified using combined gas chromatography and electroantennographic detection from the headspace of the cultivar found to be most attractive (BH-660). Synthetic blends of the volatile compounds were then assessed for attraction and oviposition preference of gravid An. arabiensis, as above.
Here the collected headspace volatiles from the pollen of two maize cultivars was shown to differentially attract and stimulate oviposition in gravid An. arabiensis. Furthermore, a five-component synthetic maize pollen odour blend was identified, which elicited the full oviposition behavioural repertoire of the gravid mosquitoes.
The cues identified from maize pollen provide important substrates for the development of novel control measures that modulate gravid female behaviour. Such measures are irrespective of indoor or outdoor feeding and resting patterns, thus providing a much-needed addition to the arsenal of tools that currently target indoor biting mosquitoes.
在撒哈拉以南非洲地区，玉米种植助长了疟蚊的繁殖，加剧了疟疾传播。玉米花粉是按蚊幼虫的重要食物来源，能够探测到玉米花粉丰富的繁殖地点的雌蚊可能会为其后代提供选择优势。据推测，按蚊利用嗅觉线索来定位、区分并选择此类地点，而且合成挥发性混合物可以模拟这些嗅觉引导行为。
采用双端口嗅觉仪和双选产卵试验，评估妊娠阿拉伯按蚊对两个玉米品种（BH - 660和ZM - 521）花粉顶空的吸引力和产卵偏好。使用气相色谱和触角电位检测联用技术，从被发现最具吸引力的品种（BH - 660）的顶空中鉴定生物活性化合物。然后，如上所述，评估挥发性化合物的合成混合物对妊娠阿拉伯按蚊的吸引力和产卵偏好。
在此研究中，从两个玉米品种花粉中收集的顶空挥发物显示出对妊娠阿拉伯按蚊有不同程度的吸引并刺激其产卵。此外，还鉴定出一种由五种成分组成的合成玉米花粉气味混合物，它引发了妊娠蚊子完整的产卵行为模式。
从玉米花粉中鉴定出的线索为开发调节妊娠雌蚊行为的新型控制措施提供了重要基础。此类措施不受室内或室外觅食和休息模式的影响，因此为目前针对室内叮咬蚊子的工具库急需增添了内容。
