Abstract:
The common bed bug, Cimex lectularius, is a hemipteran insect that feeds only on blood, and whose bites cause public health issues. Due to globalization and resistance to insecticides, this pest has undergone a significant and global resurgence in recent decades. Blood is an unbalanced diet, lacking notably sufficient B vitamins. Like all strict hematophagous arthropods, bed bugs host a nutritional symbiont supplying B vitamins. In C. lectularius, this nutritional symbiont is the intracellular bacterium Wolbachia (wCle). It is located in specific symbiotic organs, the bacteriomes, as well as in ovaries. Experimental depletion of wCle has been shown to result in longer nymphal development and lower fecundity. These phenotypes were rescued by B vitamin supplementation. Understanding the interaction between wCle and the bed bug may help to develop new pest control methods targeting the disruption of this symbiotic interaction. The objective of this work was thus to quantify accurately the density of wCle over the life cycle of the host and to describe potential associated morphological changes in the bacteriome. We also sought to determine the impact of sex, feeding status, and aging on the bacterial population dynamics. We showed that the relative quantity of wCle continuously increases during bed bug development, while the relative size of the bacteriome remains stable. We also showed that adult females harbor more wCle than males and that wCle relative quantity decreases slightly in adults with age, except in weekly-fed males. These results are discussed in the context of bed bug ecology and will help to define critical points of the symbiotic interaction during the bed bug life cycle.
摘要:
普通的臭虫,Cimexlectularius,是只以血液为食的半翅目昆虫,谁的叮咬会导致公共卫生问题。由于全球化和对杀虫剂的抗药性,近几十年来,这种害虫经历了重大的全球复苏。血液是一种不均衡的饮食,缺乏足够的B族维生素。像所有严格的食血节肢动物一样,臭虫拥有提供B族维生素的营养共生体。在C.lectularius,这种营养共生体是细胞内细菌Wolbachia(wCle)。它位于特定的共生器官中,细菌体,以及卵巢。wCle的实验性消耗已被证明会导致若虫发育更长和繁殖力更低。这些表型是通过补充B族维生素来拯救的。了解wCle与臭虫之间的相互作用可能有助于开发新的害虫防治方法,以破坏这种共生相互作用。因此,这项工作的目的是准确量化宿主生命周期中wCle的密度,并描述细菌组中潜在的相关形态变化。我们还试图确定性的影响,喂养状态,和衰老对细菌种群动态的影响。我们表明,在臭虫发育过程中,wCle的相对数量不断增加,而细菌组的相对大小保持稳定。我们还表明,成年女性比男性拥有更多的wCle,并且随着年龄的增长,成年女性的wCle相对数量略有下降。除了每周喂食的雄性。这些结果在臭虫生态学的背景下进行了讨论,将有助于确定臭虫生命周期中共生相互作用的关键点。