Institut de Recherche pour le Développement (IRD, Unité Mixte de Recherche « Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle » MIVEGEC (IRD 224-CNRS 5290-UM1-UM2), Montpellier, France.
IRD La Réunion / GIP CYROI (Recherche Santé Bio-innovation), Sainte-Clotilde, La Réunion Island, France.
PLoS One. 2018 Aug 14;13(8):e0202236. doi: 10.1371/journal.pone.0202236. eCollection 2018.
The control of Aedes albopictus through Sterile Male Releases requires that the most competitive males be mass-reared and sterilized usually with gamma- or X-ray radiation prior to release. Developing an understanding of the impact of irradiation treatment on flight performance in sterile males is very important because any fitness cost may reduce the efficacy of SIT intervention in the field. Here, we examined the role of irradiation exposure and sugar-feeding on daily flight activity and performance of Ae. albopictus males sterilized during pupal stage with gamma-radiation at 35Gray from a Caesium 137 source. We used a previously developed automated video tracking system to monitor the flight activity of different groups of sterile and control non-sterile males over 24 hours in a flight arena. This monitoring took place under controlled laboratory conditions and we wished to quantify the daily flight activity and to highlight any changes due to radiation treatment and nutritional conditions (starved versus sugar fed). Our experimental evidence demonstrated a characteristic diurnal flight activity with a bimodal pattern regardless of the treatment. Precisely, both irradiated and non-irradiated males exhibited two distinct peaks in flight activity in the morning (6-8 a.m.) and late afternoon (4-6 p.m.). Under changing physiological conditions, irradiated males were generally more active over time and flew longer overall distances than control male populations. These results suggest some internal circadian control of the phase relation to the light-dark cycle, with evidence for modification of flight performance by nutritional status. The fact that daily activity patterns are alike in irradiated and control Ae. albopictus males, and that sterile males could display higher flight performance, is in contrast with the hypothesis that irradiation treatment appears to reduce the fitness of male mosquitoes. We discuss the implications of the present study in sterile-male release programs against Ae. albopictus.
通过释放不育雄蚊来控制白纹伊蚊，需要大量饲养最具竞争力的雄性，并在释放前用γ射线或 X 射线对其进行绝育。了解辐照处理对不育雄蚊飞行性能的影响非常重要，因为任何适应能力的代价都可能降低 SIT 干预在野外的效果。在这里，我们研究了辐照暴露和喂糖对经γ射线（来自铯 137 源，35 戈瑞）在蛹期绝育的白纹伊蚊雄性的日常飞行活动和性能的影响。我们使用了一个先前开发的自动化视频跟踪系统，在飞行场地中监测不同组的不育和非不育雄性的 24 小时飞行活动。这种监测是在受控的实验室条件下进行的，我们希望量化每日飞行活动，并突出由于辐射处理和营养条件（饥饿与喂糖）而产生的任何变化。我们的实验证据表明，无论处理如何，都存在一种特征性的昼夜飞行活动，呈双峰模式。确切地说，辐照和未辐照的雄性在清晨（6-8 点）和傍晚（4-6 点）都表现出两次明显的飞行活动高峰。在不断变化的生理条件下，辐照雄性通常随着时间的推移更加活跃，总体飞行距离比对照雄性种群更长。这些结果表明，存在对与光-暗循环相位关系的内部生物钟控制，并且营养状况会影响飞行性能。在辐照和对照白纹伊蚊雄性中，每日活动模式相似，并且不育雄性可以表现出更高的飞行性能，这与辐照处理似乎降低雄性蚊子适应能力的假设形成对比。我们讨论了本研究对针对白纹伊蚊的不育雄蚊释放计划的影响。
