Chemical communication is common across all organisms. Insects in particular use predominantly chemical stimuli in assessing their environment and recognizing their social counterparts. One of the chemical stimuli used for recognition in social insects, such as ants, is the suite of long-chain, cuticular hydrocarbons. In addition to providing waterproofing, these surface hydrocarbons serve as a signature mixture, which ants can perceive, and use to distinguish between strangers and colony mates, and to determine caste, sex, and reproductive status of another individual. They can be both environmentally and endogenously acquired. The surface chemistry of adult workers has been studied extensively in ants, yet the pupal stage has rarely been considered. Here we characterized the surface chemistry of pupae of Formica exsecta, and examine differences among sexes, castes (reproductive vs. worker), and types of sample (developing individual vs. cocoon envelope). We found quantitative and qualitative differences among both castes and types of sample, but male and female reproductives did not differ in their surface chemistry. We also found that the pupal surface chemistry was more complex than that of adult workers in this species. These results improve our understanding of the information on which ants base recognition, and highlights the diversity of surface chemistry in social insects across developmental stages.

化学通讯在所有生物体中都很常见。昆虫尤其主要使用化学刺激来评估其环境并识别其社会对应物。用于社会性昆虫（例如蚂蚁）识别的化学刺激物之一是长链角质层碳氢化合物。除了提供防水之外，这些表面碳氢化合物还充当蚂蚁可以感知的特征混合物，并用它来区分陌生人和群体伙伴，并确定另一个个体的种姓、性别和生殖状态。它们可以是环境获得的，也可以是内源获得的。成年工蚁的表面化学已在蚂蚁身上进行了广泛研究，但很少考虑蛹期。在这里，我们对蚁蛹的表面化学进行了表征，并检查了性别、种姓（生殖与工蜂）和样本类型（发育中的个体与茧包膜）之间的差异。我们发现种姓和样本类型之间存在定量和定性差异，但雄性和雌性生殖体的表面化学成分没有差异。我们还发现，该物种的蛹表面化学成分比成年工蜂更复杂。这些结果提高了我们对蚂蚁识别基础信息的理解，并强调了社会性昆虫在整个发育阶段表面化学的多样性。