Abstract

In social insects, the reproductive division of labor is often regulated through communication using cuticular hydrocarbons (CHCs) that indicate caste identity and reproductive status. In many termites, workers retain reproductive potential and can differentiate into ergatoid reproductives, and this process is mediated by the presence of reproductives in sex- and age-specific patterns. However, little is known about the variation of CHCs profiles during this transition. In this study, we analyzed the CHC profiles of workers in comparison with ergatoids of different age, sex, and mating status in the eastern subterranean termite, Reticulitermes flavipes (Kollar) (Blattodea: Rhinotermitidae), one of the most widely distributed termite species in the world. Both female and male ergatoids were characterized by the presence of tricosane and a group of long-chain and methyl-branched hydrocarbons (chain length ≥ 33), which were found in significantly lower quantities from workers. In addition, CHC profiles differed between newly differentiated (3–4 d) and old (20–25 d) ergatoids, but no difference in CHC signatures was found between females and males based on identified compounds. Heneicosane, a previously reported royal recognition pheromone in R. flavipes, was not detected in ergatoids examined in this study. The results of caste- and age-dependent variations suggest that CHCs may act as releaser pheromones that mediate caste recognition and age-related interactions between reproductives, but analytical results of identified compounds in this study do not support CHCs as sex-specific primer pheromones that regulate nestmate fertility. Royal pheromones in termites may involve complex hydrocarbon blends and non-hydrocarbon substances that await further investigation.

中文翻译：

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东部地下白蚁（Blattodea：Rhinotermitidae）工人 - 生殖过渡期间表皮碳氢化合物的时间变化

摘要

在群居昆虫中，生殖分工通常通过使用表皮碳氢化合物 (CHC) 进行交流来调节，这些碳氢化合物表明种姓身份和生殖状态。在许多白蚁中，工蚁保留了繁殖潜力，可以分化为麦角类繁殖体，这一过程是由以性别和年龄特定模式存在的繁殖体介导的。然而，在这种转变过程中，对 CHCs 分布的变化知之甚少。在这项研究中，我们分析了东部地下白蚁Reticulitermes flavipes与不同年龄、性别和交配状态的麦角菌相比，工人的 CHC 概况(Kollar) (Blattodea: Rhinotermitidae)，世界上分布最广的白蚁种类之一。雌性和雄性麦角菌的特征是存在三十二烷和一组长链和甲基支链烃（链长≥ 33），从工人中发现的数量要少得多。此外，新分化的（3-4 天）和旧的（20-25 天）麦角菌的 CHC 谱不同，但根据鉴定的化合物，在雌性和雄性之间没有发现 CHC 特征的差异。Heneicosane，在先前报告的皇家识别信息素R.北美散白蚁, 在本研究中检查的类麦角中未检测到。种姓和年龄相关变异的结果表明 CHC 可能作为释放信息素，介导种姓识别和生殖之间与年龄相关的相互作用，但本研究中鉴定化合物的分析结果不支持 CHC 作为性别特异性引物信息素调节同窝繁殖能力。白蚁中的皇家信息素可能涉及复杂的碳氢化合物混合物和有待进一步调查的非碳氢化合物物质。