Department of Entomology, 2143 TAMU, Texas A&M University, College Station, TX, 77843-2143, USA.
Sci Rep. 2021 Feb 24;11(1):4471. doi: 10.1038/s41598-021-83976-6.
The production of royal pheromones by reproductives (queens and kings) enables social insect colonies to allocate individuals into reproductive and non-reproductive roles. In many termite species, nestmates can develop into neotenics when the primary king or queen dies, which then inhibit the production of additional reproductives. This suggests that primary reproductives and neotenics produce royal pheromones. The cuticular hydrocarbon heneicosane was identified as a royal pheromone in Reticulitermes flavipes neotenics. Here, we investigated the presence of this and other cuticular hydrocarbons in primary reproductives and neotenics of this species, and the ontogeny of their production in primary reproductives. Our results revealed that heneicosane was produced by most neotenics, raising the question of whether reproductive status may trigger its production. Neotenics produced six additional cuticular hydrocarbons absent from workers and nymphs. Remarkably, heneicosane and four of these compounds were absent in primary reproductives, and the other two compounds were present in lower quantities. Neotenics therefore have a distinct 'royal' blend from primary reproductives, and potentially over-signal their reproductive status. Our results suggest that primary reproductives and neotenics may face different social pressures. Future studies of these pressures should provide a more complete understanding of the mechanisms underlying social regulation in termites.
生殖蚁（蚁后和蚁王）产生的皇家信息素使群居昆虫能够将个体分配到生殖和非生殖角色中。在许多白蚁物种中，当主要蚁后或蚁王死亡时，巢内同伴可能会发育成幼态生殖蚁，从而抑制额外生殖蚁的产生。这表明主要生殖蚁和幼态生殖蚁会产生皇家信息素。二十一烷被确定为 R. flavipes 幼态生殖蚁的皇家信息素。在这里，我们研究了该物种的主要生殖蚁和幼态生殖蚁中是否存在这种和其他表皮碳氢化合物，以及主要生殖蚁中它们的产生物发生。我们的结果表明，大多数幼态生殖蚁都会产生二十一烷，这引发了一个问题，即生殖状态是否会触发其产生。幼态生殖蚁还产生了六种工蚁和若虫中不存在的其他表皮碳氢化合物。值得注意的是，二十一烷和其中四种化合物在主要生殖蚁中不存在，而另外两种化合物的含量较低。因此，幼态生殖蚁具有与主要生殖蚁不同的“皇家”混合物，并且可能过度表达其生殖状态。我们的结果表明，主要生殖蚁和幼态生殖蚁可能面临不同的社会压力。对这些压力的未来研究应该为更好地理解白蚁中社会调节的机制提供更全面的认识。
