, 1998 and Hölldobler and Wilson, 1990). The production of vitellogenin by the non-reproductive castes suggests that it has functions in addition to supplying nutrients to the embryo, which have been better characterized in bees ( Amdam et al., 2003). In A. mellifera

workers, variation in their production of vitellogenin is related to their permanence inside the colony and the onset of foraging flights ( Marco Antônio et al., 2008 and Nelson et al., 2007). Production of vitellogenin also increases the longevity of queens when compared to workers by reducing their rate of aging through resistance to oxidative stress ( Corona et al., 2007 and Seehuus et al., 2006). Vitellogenins have important functions in somatic maintenance and in the immune system of

bees ( Amdam Idelalisib price et al., 2004 and Seehuus et al., 2006), and are part of the insulin/insulin-like signaling pathway, which regulates growth, aging, and reproduction in vertebrates and invertebrates ( Corona et al., 2007). The ant species Ectatomma tuberculatum (Ectatomminae) forms colonies of up to 400 workers and one or more queens ( Hora et al., 2005). The workers have the same size and are morphologically different from queens, and perform different tasks in the colony according to Pim inhibitor their age ( Fénéron and Billen, 1996 and Fénéron et al., 1996). The workers also have active ovaries that produce trophic eggs ( Fénéron and Billen, 1996 and Hora et al., 2007) and the development of their ovaries is related to their age ( Fénéron et al., 1996). Therefore, the production of vitellogenin is related to nourishing colony members and possibly to the different activities performed by workers. In this work we test the hypothesis that the period of vitellogenin production is linked

to intranidal activities in age polyetism of E. tuberculatum workers. We find that vitellogenin is produced when workers are inside the nest acting in brood care and ceasing when workers are in activities out of the nest, suggesting that this protein can be used as a nutrient supplement PIK3C2G since the eggs produced by workers are trophic eggs that are used for queen and brood feeding. Five E. tuberculatum colonies were provided by the Laboratory of Myrmecology at the Cocoa Research Centre (CEPLAC) in Itabuna, Brazil. The ants were kept in artificial colonies built in plastic cages (18 cm × 25 cm) and filled with plaster. The colonies were connected by tubes to other cages (10 cm × 10 cm) without plaster that were used as foraging areas. All colonies were polygynous, containing two to five queens and more than 30 workers in addition to the brood. The colonies were maintained at 26 ± 2 °C and fed every two days with Tenebrio molitor (Coleoptera: Tenebrionidae) larvae, honey, and water ad libitum. In order to obtain ants with known ages, newly emerged workers were marked with an enamel paint dot on the thorax and returned to their colonies.