Dissertation Research: Ecologial Constraints and Relatedness Asymmetries in Augochlorella striata (Halictidae: Hymenoptera)

据预测，与副社会性蜂群（不存在亲缘关系不对称）的工蜂相比，真社会性膜翅目蜂群（存在亲缘关系不对称）的工蜂更倾向于偏向雌性的性别比例。对原始的真社会性汗蜂（Augochlorella striata）进行了实验，随机将蜂群分配到真社会性和副社会性，证实了社会性蜂群中雌性偏向的预测，但无法验证在副社会性蜂群中雄性工蜂的繁殖率高于社会性蜂群的假设。通过基因分析来确定雄性的母性是检验这一假设的必要条件。本研究将对实验巢穴的生殖、工蚁和雄性进行基因指纹识别，以比较群居和副群居群体中雄性工蚁的繁殖情况。由于雄性的孤雌生殖，雄性指纹上的所有条带也必须出现在其母亲的指纹上。因此，可以通过将男性的指纹与假定的母亲（如创始人和工人）的指纹相匹配来确定男性的母性。如果来自基因指纹的证据反驳了工蚁繁殖的假说，那么单倍体产生的亲缘关系不对称仍然是对观察到的性别比例调整的唯一解释。这意味着纹条草的社会行为进化不仅是对限制生殖选择的生态约束的反应，而且与单倍体性别决定系统固有的遗传变量（亲缘关系不对称）有关。

Workers in eusocial Hymenoptera colonies (relatedness asymmetry present) are predicted to favor a more female-biased sex-ratio as compared to the sex-ratio favored by workers in parasocial colonies (relatedness asymmetry absent). Experiments on the primitively eusocial sweat bee Augochlorella striata, with random assignment of colonies to a eusocial and parasocial condition confirmed the predicted female-bias in eusocial colonies, but were unable to test the hypothesis that worker reproduction of males is greater in parasocial than in eusocial colonies. The determination of maternity of males by means of a genetic analysis is essential to test this hypothesis. This study will involve genetically fingerprinting reproductives, workers, and male sexuals of the experimental nests in order to compare worker reproduction of males in eusocial and parasocial colonies. Because of parthenogenetic production of males, all bands in a fingerprint of a male must also be present in the fingerprint of his mother. Maternity of males can therefore be determined by matching fingerprints of males to fingerprints of putative mothers (e.g. foundresses and workers). If evidence from genetic fingerprinting refutes the hypothesis of worker reproduction, relatedness asymmetries deriving from haplodiploidy remain as the only explanation of the observed sex-ratio adjustments. This would imply that social behavior in A. striata evolved not only in response to ecological constraints limiting reproductive options, but also in relation to genetic variables (relatedness asymmetries) intrinsic to the haplodiploid system of sex-determination.