Phylogeny and evolution of life-history strategies in the Sycophaginae non-pollinating fig wasps (Hymenoptera, Chalcidoidea)

<p>Abstract</p> <p>Background</p> <p>Non-pollinating Sycophaginae (Hymenoptera, Chalcidoidea) form small communities within <it>Urostigma </it>and <it>Sycomorus </it>fig trees. The species show differences in galling habits and exhibit apterous, winged or dimorphic males. The large gall inducers oviposit early in syconium development and lay few eggs; the small gall inducers lay more eggs soon after pollination; the ostiolar gall-inducers enter the syconium to oviposit and the cleptoparasites oviposit in galls induced by other fig wasps. The systematics of the group remains unclear and only one phylogeny based on limited sampling has been published to date. Here we present an expanded phylogeny for sycophagine fig wasps including about 1.5 times the number of described species. We sequenced mitochondrial and nuclear markers (4.2 kb) on 73 species and 145 individuals and conducted maximum likelihood and Bayesian phylogenetic analyses. We then used this phylogeny to reconstruct the evolution of Sycophaginae life-history strategies and test if the presence of winged males and small brood size may be correlated.</p> <p>Results</p> <p>The resulting trees are well resolved and strongly supported. With the exception of <it>Apocrytophagus</it>, which is paraphyletic with respect to <it>Sycophaga</it>, all genera are monophyletic. The Sycophaginae are divided into three clades: (i) <it>Eukoebelea</it>; (ii) <it>Pseudidarnes</it>, <it>Anidarnes </it>and <it>Conidarnes </it>and (iii) <it>Apocryptophagus</it>, <it>Sycophaga </it>and <it>Idarnes</it>. The ancestral states for galling habits and male morphology remain ambiguous and our reconstructions show that the two traits are evolutionary labile.</p> <p>Conclusions</p> <p>The three main clades could be considered as tribes and we list some morphological characters that define them. The same biologies re-evolved several times independently, which make Sycophaginae an interesting model to test predictions on what factors will canalize the evolution of a particular biology. The ostiolar gall-inducers are the only monophyletic group. In 15 Myr, they evolved several morphological adaptations to enter the syconia that make them strongly divergent from their sister taxa. Sycophaginae appears to be another example where sexual selection on male mating opportunities favored winged males in species with small broods and wingless males in species with large broods. However, some species are exceptional in that they lay few eggs but exhibit apterous males, which we hypothesize could be due to other selective pressures selecting against the re-appearance of winged morphs.</p

Figfigwasp mutualism: The fall of the strict cospeciation paradigm?

At least three classic systems of nursery pollination mutualism are known: the fig (Ficus, Moraceae) – agaonid (Hymenoptera, Chalcidoidea) association (Cook and Rasplus 2003), the yucca (Yucca, Hesperoyucca; Agavaceae) – yucca moths (Tegeticula, Parategeticula; Lepidoptera, Prodoxidae) association (Pellmyr 2003) and the Glodichion (Phyllanthaceae) – Epicephala moths (Lepidoptera, Gracillariidae) association (Kato et al. 2003). All these mutualisms are obligate, which means that each partner depends on the other for its own reproductive success. The insect pollinates the flowers and oviposits in the plant ovaries where the insect larvae subsequently feed on a subset of the developing seeds. A shift from mutualism to parasitism by the pollinating insect would lead to reproduction failure of the plant and, without host shift, to the extinction of both lineages. Therefore, the speciation of mutualistic pollinators is generally believed to be driven by the speciation of their host-plants. In this hypothesis, when an ancestral plant species splits into two daughter species, its mutualistic pollinator also splits. This scenario should result in perfect congruence of hosts and pollinator phylogenies (Farenholz's rule) (Farenholz 1913). However, this seems increasingly unlikely. Indeed, more and more studies on different coevolved associations show that a strict Farenholz's rule is not respected, even when a high level of host specificity exists (e.g. Paterson and Banks 2001; Desdevises et al. 2002; Charleston and Perkins 2006). Topological incongruence between host and associate phylogenetic trees can result from processes like host switching, sorting events (extinction and lineage sorting), duplication events (speciation of the parasite independent of the host), and failure of the associate to diverge when the host diverges (“missing the boat”) (Page 1991; Page 1994; Page and Charleston 1998; Legendre et al. 2002; Charleston and Perkins 2006). © The Systematics Association 2012

Fig-fig wasp mutualism : the fall of the strict cospeciation paradigm?

At least three classic systems of nursery pollination mutualism are known: the fig (Ficus, Moraceae) - agaonid (Hymenoptera, Chalcidoidea) association (Cook and Rasplus 2003), the Yucca, Hesperoyucca; Agavaceae) –yucca moths (Tegeticula, Parategeticula; Lepidoptera, Prodoxidae) association (Pellmyr 2003) and the Glodichion (Phyllanthaceae) – Epicephala moths (Lepidoptera, Gracillariidae) association (Kato et al. 2003). All these mutualism are obligate, which means that each partner depends on the other for its own reproductive success. The insect pollinates the flowers and oviposits in the plant ovaries where the insect larvae subsequently feed on a subset of the developing seeds. A shift from mutualism to parasitism by the pollinating insect would lead to reproduction failure of the plant and, without host shift, to the extinction of both lineages. Therefore, the speciation of mutualistic pollinators is generally believed to be driven by the speciation of their host-plants. In this hypothesis, when an ancestral plant species splits into two daughter species, its mutualistic pollinator also splits. This scenario should result in perfect congruence of hosts and pollinator phylogenies (Farenholz’s rule) (Farenholz 1913). However, this seems increasingly unlikely. Indeed, more and more studies on different coevolved associations show that a strict Farenholz’s rule is not respected, even when a high level of host specificity exists (e.g. Paterson and Banks 2001); Desdevises et al. 2002; Charleston and Perkins 2006)

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora