Division of labor is fundamental to the ecological success of social insects. In termites, both sexes engage in social tasks, and the sexual division of labor is common in many taxa. Each caste consisting of both sexes is supplied from the population of newly hatched larvae. To understand their social system, it is necessary to investigate the influence of larval sex composition on their developmental fate. However, no method currently exists for sexing young larvae non-invasively, which is essential for experimental manipulation of the sex composition in a society. Here, we report on sex-specific characteristics of the first and second instar larvae of the subterranean termite Reticulitermes speratus. Male larvae possess bristles near the center of the posterior margin of the eighth abdominal sternite that are absent in females. The bristles are detectable under a stereomicroscope without damaging the young instar larvae. The validity of morphological sexing was confirmed by a known sex-specific genetic marker. The sex-specific bristles were also useful to identify the sex of first and second instar larvae of the damp-wood termite Zootermopsis nevadensis, suggesting that morphological sexing is possible for a wide range of termite species. The morphological sexing presented here has broad applicability in studies addressing sex differences in development, caste differentiation, and behavior. These approaches will contribute to understanding why both sexes co-exist in a termite society and allocate tasks, and which tasks are completely compensable by the other sex, thereby deepening our understanding of social systems where both sexes engage in tasks.

中文翻译：

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一种利用外部形态对白蚁一龄和二龄幼虫进行性别鉴定的非侵入性方法

分工是群居昆虫生态成功的基础。在白蚁中，两性都从事社会任务，在许多分类群中，性别分工很常见。由两性组成的每个种姓均由新孵化的幼虫种群提供。为了了解它们的社会系统，有必要调查幼虫性别组成对其发育命运的影响。然而，目前尚无非侵入性对年轻幼虫进行性别鉴定的方法，这对于社会中性别组成的实验操作至关重要。在这里，我们报告了地下白蚁 Reticulitermes speratus 的第一和第二龄幼虫的性别特异性特征。雄性幼虫在第八腹部胸骨后缘的中心附近具有刚毛，雌性没有。刷毛可在立体显微镜下检测到，而不会损坏幼虫。形态性别的有效性由已知的性别特异性遗传标记证实。性别特异性刚毛也可用于识别潮湿木白蚁 Zootermopsis nevadensis 的一龄和二龄幼虫的性别，这表明对广泛的白蚁物种进行形态性别区分是可能的。这里介绍的形态性别划分在解决发育、种姓分化和行为方面的性别差异的研究中具有广泛的适用性。这些方法将有助于理解为什么在白蚁社会中两性共存并分配任务，以及哪些任务可以由另一性别完全补偿，从而加深我们对两性参与任务的社会系统的理解。