Moller-Jacobs Lillian L, Murdock Courtney C, Thomas Matthew B
Center for Infectious Disease Dynamics and Department of Entomology, Merkle Lab, Pennsylvania State University, Orchard Road, University Park, PA, 16802, USA.
College of Veterinary Medicine, Odum School of Ecology, University of Georgia, DW Brooks Drive, Athens, GA, 30602, USA.
Parasit Vectors. 2014 Dec 14;7:593. doi: 10.1186/s13071-014-0593-4.
Adult traits of holometabolous insects such as reproduction and survival can be shaped by conditions experienced during larval development. These "carry-over" effects influence not only individual life history and fitness, but can also impact interactions between insect hosts and parasites. Despite this, the implications of larval conditions for the transmission of human, wildlife and plant diseases that are vectored by insects remain poorly understood.
We used Anopheles stephensi mosquitoes and the rodent malaria, Plasmodium yoelii yoelii, to investigate whether quality of larval habitat influenced vectorial capacity of adult mosquitoes. Larvae were reared under two dietary conditions; one group received a diet commonly used for colony maintenance (0.3 mg/individual/day of Tetrafin fish food) while the other group received a reduced food diet (0.1 mg/individual/day). Upon emergence, adults were provided an infectious blood feed. We assessed the effects of diet on a range of larval and adult traits including larval development times and survival, number of emerging adults, adult body size and survival, gonotrophic cycle length, and mating success. We also estimated the effects of larval diet on parasite infection rates and growth kinetics within the adult mosquitoes.
Larval dietary regime affected larval survival and development, as well as size, reproductive success and survival of adult mosquitoes. Larval diet also affected the intensity of initial Plasmodium infection (oocyst stage) and parasite replication, but without differences in overall infection prevalence at either the oocyst or sporozoite stage.
Together, the combined effects led to a relative reduction in vectorial capacity (a measure of the transmission potential of a mosquito population) in the low food treatment of 70%. This study highlights the need to consider environmental variation at the larval stages to better understand transmission dynamics and control of vector-borne diseases.
全变态昆虫的成虫特征，如繁殖和生存，可能受到幼虫发育期间所经历条件的影响。这些“遗留”效应不仅影响个体的生活史和适应性，还会影响昆虫宿主与寄生虫之间的相互作用。尽管如此，幼虫条件对由昆虫传播的人类、野生动物和植物疾病的影响仍知之甚少。
我们使用斯氏按蚊和啮齿动物疟疾约氏疟原虫，来研究幼虫栖息地质量是否会影响成年蚊子的传播能力。幼虫在两种饮食条件下饲养；一组接受常用于维持种群的饮食（0.3毫克/个体/天的 Tetrafin 鱼食），而另一组接受减少的食物饮食（0.1毫克/个体/天）。羽化后，为成虫提供感染性血餐。我们评估了饮食对一系列幼虫和成虫特征的影响，包括幼虫发育时间和存活率、羽化成虫的数量、成虫体型和存活率、生殖营养周期长度以及交配成功率。我们还估计了幼虫饮食对成年蚊子体内寄生虫感染率和生长动力学的影响。
幼虫饮食方案影响幼虫的存活和发育，以及成年蚊子的体型、繁殖成功率和存活率。幼虫饮食还影响疟原虫初始感染（卵囊阶段）的强度和寄生虫复制，但在卵囊或子孢子阶段的总体感染率没有差异。
综合起来，这些综合效应导致低食物处理组的传播能力（衡量蚊子种群传播潜力的指标）相对降低了70%。这项研究强调需要考虑幼虫阶段的环境变化，以更好地理解媒介传播疾病的传播动态和控制。
