Key Laboratory of Biotic Environment and Ecological Safety in Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui Province, China.
Insect Sci. 2013 Apr;20(2):228-34. doi: 10.1111/j.1744-7917.2011.01495.x. Epub 2012 Apr 28.
Local mate competition theory predicts that offspring sex ratio in pollinating fig wasps is female-biased when there is only one foundress, and increased foundress density results in increased offspring sex ratio. Information of other foundresses and clutch size have been suggested to be the main proximate explanations for sex ratio adjustment under local mate competition. Our focus was to show the mechanism of sex ratio adjustment in a pollinating fig wasp, Ceratosolen solmsi Mayr, an obligate pollinator of the functionally dioecious fig, Ficus hispida Linn., with controlled experiments in the field. First, we obtained offspring from one pollinator and offspring at different oviposition sequences, and found that offspring sex ratio decreased with clutch size, and pollinators produced most of their male offspring at the start of bouts, followed by mostly females. Second, we found that offspring sex ratio increased with foundress density, and pollinators did adjust their offspring sex ratio to other females in the oviposition patches. We suggest that when oviposition sites are not limited, pollinators will mainly adjust their offspring sex ratio to other foundresses independent of clutch size changes, whereas adjusting clutch size may be used to adjust sex ratio when oviposition sites are limited.
本地配偶竞争理论预测，当只有一个育母时，传粉榕小蜂的后代性别比例偏向雌性，而育母密度的增加会导致后代性别比例增加。其他育母的信息和卵的数量被认为是本地配偶竞争下性别比例调整的主要直接解释。我们的重点是展示一种传粉榕小蜂 Ceratosolen solmsi Mayr 的性别比例调整机制，这种榕小蜂是功能上雌雄异株的榕果的专性传粉者，与在野外进行的对照实验相结合。首先，我们从一个传粉者那里获得了后代，以及在不同产卵序列下的后代，发现后代的性别比例随着卵的数量减少而减少，而且传粉者在开始产卵时产生了大部分雄性后代，随后则是大部分雌性后代。其次，我们发现后代的性别比例随着育母密度的增加而增加，传粉者确实会根据产卵点中的其他育母的情况来调整其后代的性别比例。我们认为，当产卵点不受限制时，传粉者将主要根据其他育母的情况来独立调整其后代的性别比例，而在产卵点受到限制时，调整卵的数量可能会被用来调整性别比例。
