近日，国际学术期刊《Cell》子刊《Current Biology》在线发表了巴西农业研究合作中心Cristiano Menezes研究员的一篇研究文章，研究指出蜜蜂培育真菌喂养幼蜂，为幼虫提供额外的食物。
似乎只有花朵还不够。尽管很多群居昆虫如蚂蚁和白蚁都会“耕作食物”，但科学家一直以来认为蜜蜂仅依靠花粉和糖浆哺育后代。
但是对于巴西无刺蜜蜂Scaptotrigona depilis来说，真菌就意味着能否生存。更重要的是,如果其他蜜蜂也依赖于真菌生存,发现严重影响了农业杀菌剂的使用。
当巴西农业研究合作中心的Cristiano Menezes在实验室中研究蜜蜂时，他们一开始把蜂巢中生长的白色红曲霉真菌误认为是污染物。
但当他发现它在所有30蜂巢他看着,他开始怀疑这是有原因的,特别是因为它是生长在窝细胞——社会蜜蜂建造房子的结构不断增长的幼虫。
他和他的团队发现,真菌是一个蜂巢的关键部分。它渗透到耵聍,这种由蜜蜂蜡和树脂制成的材料作为建筑材料。蜜蜂为了细胞内的幼虫沉积反刍食物后,产了卵,之后真菌开始增长。
卵孵化后,幼虫吃真菌,事实证明这种食物绝对是至关重要的。当研究团队试图在没有真菌的实验室培育蜜蜂,幼虫的存活率仅大幅下降,从72%减少到8%。他们说“这么大存活率的差异可能是由于真菌提供了一些营养,或由于真菌保护反刍食物不被腐坏所造成的”。
当蜜蜂离开开始一个新地方,他们带着一些耵聍建造新蜂巢结构,所以他们的真菌农场来了。荷兰瓦赫宁根大学的Duur Aanen说“很明显,这种真菌有利于蜜蜂传播繁殖,在新地方和巢内提供一个受保护的环境”。
“这是一个激动人心的例子：发现复杂的昆虫和微观的生活之间的联系,”威斯康辛大学的卡梅隆库里说。”,它说明了互利共生体昆虫的重要角色。
原文链接：A Brazilian Social Bee Must Cultivate Fungus to Survive
原文摘要：The nests of social insects provide suitable microenvironments for many microorganisms as they offer stable environmental conditions and a rich source of food . Microorganisms in turn may provide several benefits to their hosts, such as nutrients and protection against pathogens. Several examples of symbiosis between social insects and microorganisms have been found in ants and termites. These symbioses have driven the evolution of complex behaviors and nest structures associated with the culturing of the symbiotic microorganisms. However, while much is known about these relationships in many species of ants and termites, symbiotic relationships between microorganisms and social bees have been poorly explored. Here, we report the first case of an obligatory relationship between the Brazilian stingless bee Scaptotrigona depilis and a fungus of the genus Monascus (Ascomycotina). Fungal mycelia growing on the provisioned food inside the brood cell are eaten by the larva. Larvae reared in vitro on sterilized larval food supplemented with fungal mycelia had a much higher survival rate (76%) compared to larvae reared under identical conditions but without fungal mycelia (8% survival). The fungus was found to originate from the material from which the brood cells are made. Since the bees recycle and transport this material between nests, fungus would be transferred to newly built cells and also to newly founded nests. This is the first report of a fungus cultivation mutualism in a social bee.
