Do eggs convey information on gamergate presence in Diacamma sp. from Japan?

Abstract

In eusocial Hymenoptera, information on the presence of a queen is considered to play an important role in regulating worker reproduction. We examined the mode of transmission of this putative queen information to workers. Previous studies have reported that, in Diacamma sp. from Japan, unmated helper workers perceive the presence of a gamergate (functional queen) only through direct physical contact with her. In contrary to this conclusion, we showed, by an experiment that exposed workers either to the gamergate or to the eggs laid by the gamergate, that the presence of eggs laid by the gamergate to some extent suppressed the workers' dominance interaction, a behavior that is associated with self-reproduction by unmated workers. We discuss the relative importance of direct and indirect transmission of gamergate-presence information under natural conditions in this ant.

Egg discrimination by workers in Diacamma sp. from Japan

“…Future studies should test the hypothetical roles that SHCs and CHCs play in worker policing and fertility signaling in Diacamma sp. (see also Kikuta and Tsuji, 1999;Tsuji et al, 1999;Kikuchi et al, 2010;Shimoji et al, 2011), as examined in C. floridanus (Endler et al, 2004;2006). A bioassay would determine whether the above-mentioned SHCs trigger worker policing behavior in Diacamma sp.…”

“…were collected in Nakijin, a village on the main island of Okinawa, from May to June 2005 and in May 2007. Each colony was housed in a ''double container'' artificial nest (Shimoji et al, 2011), which comprises a small plastic container (10 cm 9 10 cm 9 2.5 cm high) that serves as a breeding chamber in the center of a larger container (15 cm 9 21 cm 9 13.5 cm high). These colonies were maintained in the laboratory (25 ± 1°C, 12 L:12 D cycle) for 2-3 months before the experiment began.…”

Social enforcement depending on the stage of colony growth in an ant

“…All colonies were collected between 1997 and 2008 in Nakijin on Okinawa Island, Japan. Each colony was housed in a standard artificial nest [29] and kept in the laboratory (26 + 18C, 14 L : 10 D cycle). They were fed ad libitum on mealworms and water.…”