Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India.
Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India
Proc Natl Acad Sci U S A. 2018 Jan 23;115(4):756-761. doi: 10.1073/pnas.1714006115. Epub 2018 Jan 8.
In most primitively eusocial wasps new nests are initiated by a single female or by small groups of females. To study the emergence of division of labor (DOL) among the nest foundresses and to determine its possible effect on nest productivity we maintained newly eclosed females of in small boxes with one, two, or three nestmate wasps of the same age per box. Only one wasp developed her ovaries and laid eggs in each box, while the other wasp(s) built the nest, brought food, and fed larvae, demonstrating the spontaneous emergence of reproductive DOL in the presence of more than one wasp. In nests with three wasps there was also a strong negative correlation between intranidal and extranidal work performed by the two nonreproductive workers, suggesting the spontaneous emergence of nonreproductive DOL; such nonreproductive DOL was absent in nests with two wasps. Both reproductive and nonreproductive DOL were modulated by dominance behavior (DB). In nests with two wasps the egg layer showed significantly more DB than the non-egg layer before nest initiation; in nests with three wasps queens showed significantly more DB than intranidal workers, which in turn showed significantly more DB than extranidal workers. Productivities of nests (as measured by total brood on the day of eclosion of the first adult) initiated by one or two wasps were not different from each other but were significantly lower than that of three wasps. Thus, nonreproductive DOL, and not merely reproductive DOL, is necessary for increase in productivity.
在大多数原始真社会性黄蜂中，新巢由一只或几只雌蜂或少数几只雌蜂开始建立。为了研究巢建造者之间分工（DOL）的出现，并确定其对巢生产率的可能影响，我们在小盒子里饲养新羽化的 ，每个盒子里有一只、两只或三只年龄相同的巢伴黄蜂。每个盒子里只有一只黄蜂发育卵巢并产卵，而其他黄蜂则建造巢穴、带来食物并喂养幼虫，这表明在有一只以上黄蜂存在的情况下，生殖 DOL 会自发出现。在有三只黄蜂的巢中，非生殖性工人在巢内和巢外的工作之间也存在强烈的负相关，表明非生殖性 DOL 会自发出现；在有两只黄蜂的巢中，这种非生殖性 DOL 不存在。生殖性和非生殖性 DOL 都受到支配行为（DB）的调节。在有两只黄蜂的巢中，产卵者在巢开始前比非产卵者表现出明显更多的 DB；在有三只黄蜂的巢中，蜂王比巢内工蜂表现出明显更多的 DB，而巢内工蜂又比巢外工蜂表现出明显更多的 DB。由一只或两只黄蜂开始的巢的生产率（以第一批成虫出壳当天的总幼虫数来衡量）彼此之间没有差异，但明显低于三只黄蜂开始的巢。因此，非生殖性 DOL，而不仅仅是生殖性 DOL，对于提高生产率是必要的。
