Seasonal cycle of colony structure in the Ponerine ant Pachycondyla chinensis in western Japan (Hymenoptera, Formicidae)

Abstract

Investigation of reproductive strategies of ants in the subfamily Ponerinae is important for understanding of the evolution of social structure and of the significance of caste dimorphisms. The biology of species with mated and egg-laying workers (gamergates) has been studied for many species, however, little attention has been paid to species that reproduce via alate queens only. We investigated the seasonal cycle of changes in the colony structure of Pachycondyla chinensis reproduced by alate queens in western Japan, and found the following novel biological characteristics of this species. P. chinensis showed a remarkable caste dimorphism in ovariole numbers: workers had no ovaries while queens had 18 to 36 ovarioles in their ovaries. The nesting system seemed to be polydomous: 266 of 400 nests collected were queenless. The number of queenless nests increased during the reproductive season. Among the 134 queenright nests, 38 had several mated-queens without significant differences in ovary activation and the remaining 96 nests were monogynous. During winter to early spring, most nests were polygynous. After alate production, most of the old queens seemed to die or be expelled and replaced by new queens. Virgin dealated queens were often found and they seemed to have laid eggs.

Forest invader replaces predation but not dispersal services by a keystone species

“…They are known as termite specialists both in their home and invaded ranges (Bednar and Silverman 2011;Matsuura 2002). B. chinensis forms colonies that range from a few dozen to thousands of workers, some without queens, some with multiple queens, and workers may move between colonies (Creighton 1950;Gotoh and Ito 2008;Zungoli and Benson 2008).…”

Seasonal cycle of the nest composition in the Ponerine ant Cryptopone sauteri (Hymenoptera: Formicidae)

“…There were not consistent results on the existence of overwinter larvae in poneroid ants. The lack of overwinter larvae in the nests were reported in some Ponerine ants Brachyponera chinensis and Odontomachus brunneus (Gotoh & Ito, 2008; Hart & Tschinkel, 2012), while Talbot (2012) reported that Ponera differed from Amblyopone or Proceratium in that it did not overwinter larvae. In C. sauteri, the developed larvae were collected even in the beginning of spring (May), strongly suggesting that larvae overwinter.…”

“…For example, "Encyclopedia of Japanese ants", which was published in 2014, listed more than 290 species in Japan and provided important taxonomic descriptions; however, the life histories and biological characteristics of the listed ant species have not yet been examined in detail (Terayama et al, 2014). Life history data are indispensable to establish molecular and chemical studies (Schlick-Steiner et al, 2005;Katzerke et al, 2006;Purcell & Chapuisat, 2012).of life history with the sampling of enough nests have been available for only two species of Ponerinae ants (Gotoh & Ito, 2008;Hart & Tschinkel, 2012). Gotoh and Ito (2008) reported all adults of Brachyponera chinensis emerged once a year, and brood are not present in the nests during the winter.…”

“…Life history data are indispensable to establish molecular and chemical studies (Schlick-Steiner et al, 2005;Katzerke et al, 2006;Purcell & Chapuisat, 2012).of life history with the sampling of enough nests have been available for only two species of Ponerinae ants (Gotoh & Ito, 2008;Hart & Tschinkel, 2012). Gotoh and Ito (2008) reported all adults of Brachyponera chinensis emerged once a year, and brood are not present in the nests during the winter. Hart and Tschinkel (2012) reported the colonies of Odontomachus brunneus produce brood for 6 months and are broodless for 6 months that includes the winter in north Florida.…”

Nest Emigration Behavior of the Asian Needle Ant, Brachyponera (=Pachycondyla) chinensis Emery (Hymenoptera: Formicidae)

“…The loss of worker egg production ensures that queens are the sole producer of life within a colony making her a vital asset to the longevity of the colony. Worker ants of B. chinensis (Ito and Ohkawara, 1994) and its sister species B. nakasujii do not possess ovarioles (Gotoh & Ito, 2008). As a result, B. chinensis colonies solely depend on the queen for egg production.…”