Molecular phylogenies of figs and fig-pollinating wasps in the Ryukyu and Bonin (Ogasawara) islands, Japan

Abstract

The interaction between figs (Ficus, Moraceae) and fig-pollinating wasps (Chalcidoidea, Agaonidae) is one of the most specific mutualisms, and thus is a model system for studying coevolution and cospeciation. In this study we focused on figs and their associated fig-wasps found in the Ryukyu and Bonin (Ogasawara) Islands, Japan, because it has been suggested that breakdown in the specificity may occur in islands or at edge of a species' distribution. We fig-wasps (B. nipponica), respectively, and probably migrated from the Ryukyu Islands.

Phylogenetic analyses suggest a hybrid origin of the figs (Moraceae: Ficus) that are endemic to the Ogasawara (Bonin) Islands, Japan

“…1 [Azuma et al, 2010]). At least for the Japanese figs, recent studies indicate that each fig species is pollinated by a single wasp species (the oneto-one rule) (Yokoyama and Iwatsuki, 1998;Azuma et al, 2010). Molecular phylogenetic analyses support co-cladogenesis between the Japanese figs and their pollinating wasps, suggesting host changes have not occurred in the Japanese pollinating wasps (Azuma et al, 2010).…”

“…The northern limits of the distribution of other Japanese species are mainly restricted to the Ryukyu Islands (refer to Fig. 1 [Azuma et al, 2010]). At least for the Japanese figs, recent studies indicate that each fig species is pollinated by a single wasp species (the oneto-one rule) (Yokoyama and Iwatsuki, 1998;Azuma et al, 2010).…”

A living fossil fig wasp (Hymenoptera, Agaoninae) developing in extant Neotropical fig species (Moraceae: Ficus, section Pharmacosycea)

“…Berg (2009) (Corner, 1967), North Atlantic land bridges (Cruaud et al, 2012) or long distance trans-oceanic dispersal, proposed for the association Tetrapus-Pharmacosycea in the New World (cf. Corner, 1967;Rønsted et al, 2005;Lopez-Vaamonde et al, 2009;Azuma et al, 2010;Cruaud et al, 2011). Furthermore, it questions the radiation of Ficus during the Tertiary after the break-up of Gondwana proposed by Zerega et al (2005) and Cruaud et al (2011).…”

“…Rønsted et al (2005) fig-pollinating wasps). However, the Tetrapus species molecularly analyzed by those authors, as well as others, correspond to extant Tetrapus Machado et al, 1996;Jousselin, Rasplus, & Kjellberg, 2003;Datwyler & Weiblen, 2004;Rønsted et al, 2005;2008;Jian, Zhu, & Zhen, 2006;Lopez-Vaamonde et al, 2009;Azuma et al, 2010;Erasmus, van Noort, Jousselin, & Greeff, 2010;Munro et al, 2011;Cruad et al, 2009Cruad et al, , 2011Cruad et al, , 2012. The objectives of this work were to study the association of five Tetrapus morphotypes whose females have two independent mandibular appendages and hexapodous males; explain their origin and morphological relationships to other pollinating wasps of subgenus Pharmacosycea and other pollinating genera, their taxonomic position, and its origin.…”

“…It is found in all regions where frost does not occur (Corner, 1958), especially in areas of the Southern Hemisphere, including very small isolated oceanic islands (McKey, 1989;Yokoyama, 2003;Azuma, Harrison, Nakamura, & Su, 2010;Ramírez, Gómez, Salazar, & Aguilar, 2011 (Berg, 1989), comprising at least 25 species (Berg, 2009), of which 19 are found in Ecuador. Ficus is characterized by its unique flask-like urceolate inflorescence (fig or syconium) with internal staminate and pistillate flowers and a small circular or split-shaped terminal orifice, the ostiolum, barred by stiff bracts, through which the symbiotic pollinating wasps must pass to reach the syconial cavity, oviposit in some of the female florets that become galls, where their larvae develop, and pollinate some of them that become seeds.…”