Mullins Aaron, Su Nan-Yao
Department of Entomology and Nematology, Fort Lauderdale Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Fort Lauderdale, FL 33314, USA.
Insects. 2018 Mar 26;9(2):37. doi: 10.3390/insects9020037.
Colony foundation and early growth is a critical period in the life-cycle of a termite colony, as the initial family unit is resource limited. One such resource is nitrogen, which is essential for initial colony growth. This study examined the whole-colony nitrogen inventory during foundation and early growth of Shiraki colonies. It was hypothesized that termite colonies would go through an initial period of parental investment, representing a transfer of nitrogen to the first brood, and that once a functional worker caste was present, further provisioning in the form of intrinsic N₂ fixation would occur. Our results showed that, when in nitrogen-poor rearing conditions, the king and queen initially transferred half of their nitrogen reserves to their first brood. However, the total nitrogen content in colonies did not increase over a 12 month period, despite the presence of functional workers. Furthermore, colonies did not increase their biomass beyond the initial parental investment. Together, these results imply that nitrogen acquisition in incipient colonies relies on environmental or dietary sources, rather than the putative fixation through symbiotic diazotrophs.
蚁群的建立和早期生长是白蚁蚁群生命周期中的一个关键时期，因为最初的家庭单位资源有限。氮就是这样一种资源，它对蚁群的初始生长至关重要。本研究考察了白蚁白木原蚁蚁群建立和早期生长过程中的全蚁群氮存量。研究假设，白蚁蚁群会经历一个亲代投资的初始阶段，即向第一批幼虫转移氮，并且一旦出现功能性工蚁等级，就会以内在固氮的形式进行进一步供应。我们的结果表明，在氮含量低的饲养条件下，蚁王和蚁后最初将其一半的氮储备转移给了它们的第一批幼虫。然而，尽管有功能性工蚁存在，蚁群中的总氮含量在12个月内并未增加。此外，蚁群的生物量没有超过最初的亲代投资而增加。这些结果共同表明，初期蚁群的氮获取依赖于环境或饮食来源，而非通过共生固氮菌进行假定的固氮作用。
