Abstract

Sex allocation is one of the most studied traits in evolutionary biology because its theoretical predictions match the empirical data. Here, using the Ryukyu dry-wood termite Neotermes sugioi, we investigated several factors that could bias the sex allocation in three populations (Okinawa, Ishigaki/Iriomote, and Yonaguni). Our survey showed that there were more queen-only colonies than king-only colonies in these populations, suggesting a longer lifespan of the queens than that of the kings. In this condition, sex-asymmetric reproductive value (SRV) theory predicts female bias, because even after the short-lived kings die, the long-lived queens can continue reproduction with their sons. However, sex allocation in this species seemed to be biased toward males. Furthermore, we examined the possibility of intrasexual competition among siblings (ICS). If ICS is the cause of the bias, the allocation is expected to change depending on the total investment in sexual offspring. However, the biomass of both male and female alates increased linearly with the increase in the total biomass of the alates in these populations. Thus, neither the SRV nor the ICS theory could explain the male-biased sex ratio of N. sugioi. On the basis of these results, we discuss the remaining possibilities in this species.

Details

Title
Caste development and sex ratio of the Ryukyu drywood termite Neotermes sugioi and its potential mechanisms
Author
Miyaguni, Y 1 ; Agarie, A 2 ; Sugio, K 3 ; Tsuji, K 4 ; Kobayashi, K 5 

 University of the Ryukyus, Global Education Institute, Okinawa, Japan (GRID:grid.267625.2) (ISNI:0000 0001 0685 5104) 
 Kagoshima University, Department of Environmental Science and Conservation Biology, United Graduate School of Agricultural Sciences, Kagoshima, Japan (GRID:grid.258333.c) (ISNI:0000 0001 1167 1801) 
 University of the Ryukyus, Graduate School of Education, Nishihara, Japan (GRID:grid.267625.2) (ISNI:0000 0001 0685 5104) 
 University of the Ryukyus, Entomological Laboratory, Faculty of Agriculture, Okinawa, Japan (GRID:grid.267625.2) (ISNI:0000 0001 0685 5104) 
 Hokkaido Forest Research Station, Kyoto University, Field Science Education and Research Center, Hokkaido, Japan (GRID:grid.258799.8) (ISNI:0000 0004 0372 2033) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2554123198
Copyright
© The Author(s) 2021. corrected publication 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.