Predation on the pollinating fig wasp of Ficus erecta by larvae of Silba sp. (Diptera: Lonchaeidae)

This study examined the insect assemblage within the syconium of the dioecious fig Ficus erecta Thunb., 1786 (Moraceae) on Kii‐Oshima Island, Wakayama Prefecture, Japan. Species present included pollinating and non‐pollinating fig wasps Blastophaga nipponica Grandi, 1921 and Sycoscapter inubiae Ishii, 1934, respectively, as well as an undetermined species of Silba Macquart, 1851 (Diptera: Lonchaeidae). Larvae of Silba sp. were found only in fig syconia containing B. nipponica. Observations revealed that larvae of Silba sp. fed on female adults of B. nipponica within fig galls by thrusting their heads through the intersegmental membrane. Furthermore, larvae of Silba sp. had a high predation rate (90%). These observations suggest that larvae of Silba sp. are specialized for feeding on B. nipponica and have a negative effect on populations of this species.     

Phenology and Pollination Ecology of Three Brazilian Fig Species (Moraceae)

The phenology and pollination ecology of three native fig species were studied in southeastern Brazil. Populations displayed continual syconia production, with one species showing intra-tree flowering asynchrony. Pollination of the fig flowers was necessary for the development of the syconia; lack of pollination induced abortion of syconia. All three species follow the general pattern of pollination known for figs, but the behavior of the pollinator wasps, Pegoscapus spp., differed in some aspects from those of other neotropical and paleotropical fig wasps, mainly with respect to pollen loading and unloading during pollination. The longevity of Pegoscapus wasps outside the syconium was about two days.     

The Flight Heights of Chalcid Wasps (Hymenoptera,Chalcidoidea) in a Lowland Bornean Rain Forest: Fig Wasps are the High Fliers1

Tropical rain forests are characterized by their rich plant diversity and highly diverse insect faunas containing mainly rare species. Phytophagous and parasitoid insects utilizing such fragmented resources often must travel considerable distances to find suitable hosts. For small, weak‐flying insects, entry into the fast‐flowing air above the canopy can provide one way by which long‐distance dispersal is achieved. Using sticky traps placed at different heights in a lowland rain forest of Borneo, we compared the diurnal and nocturnal flight heights of chalcids, a group of mainly very small parasitoids and phytophages, to determine if the air above the canopy was used for dispersal. Most families were represented throughout the range of trap heights, including those above the general canopy. A higher proportion of individuals were trapped above the canopy at night than during the day. Fig wasps were exceptional in that they were trapped almost entirely above the canopy. They included species associated with host trees that do not fruit in the canopy, suggesting that these short‐lived, slow‐flying insects actively fly up above the canopy and then use the wind to passively carry them the long distances needed to reach their highly localized and ephemeral hosts. Once the fig wasps detect the species‐specific volatiles released by their host figs, they then may fly down into the canopy, where the lower wind speeds would allow them to fly actively upwind to their hosts.     

Development and characterization of microsatellite markers for a fig‐pollinating wasp (Ceratosolen sp. 1) of Ficus septica

For an undescribed fig‐pollinating wasp (Ceratosolen sp. 1) of Ficus septica, we isolated 15 polymorphic microsatellite markers from a genomic library partially enriched for GATA and CAG repeats. Polymorphism of these loci was evaluated by genotyping 40 female individuals collected from different fruits of host trees in southern Taiwan. The number of alleles per locus ranged from three to 15 and the observed heterozygosity of each locus ranged from 0.100 to 0.775. These loci would be suitable for further studies concerning population genetics, hybridization and sex ratio adjustment of the coexisting fig‐pollinating wasps.     

粗叶榕(Ficus hirta)繁殖系统的特征及其共生的榕小蜂

本文对粗叶榕(Ficus hirta Vahl)的外部形态、花序结构以及寄主和传粉者的繁殖特性作了比较详细的观察和研究, 讨论了它们互惠共生关系的一些基本特征。它的专性传粉者是榕小蜂科(Agaonidae)榕小蜂亚科(Agaoninae)的爪哇榕小蜂(Blastophaga javana Mayr)。观察发现粗叶榕还存在两种非授粉小蜂Sycoscapter sp.和Philotrypesis sp.,它们在榕果外产卵。     

粗叶榕（Focis hirta）繁殖系统的特征及其共生的榕小蜂

本文对粗叶榕(Focis hirta)的外部形态、花序结构以及寄主和传粉者的繁殖特性作了比较详细的观察和研究,讨论了它们互惠共生关系的一些基本特征。它的专性传粉者是榕小蜂科(Agaonidae)榕小蜂亚科(Agaoninae)的爪哇榕小蜂(Blastophaga javana Mayr)。观察发现粗叶榕还存在两种非授粉小蜂Sycoscapter sp．和Philotrypesis sp．,它们在榕果外产卵。     

Non‐pollinating cheater wasps benefit from seasonally poor performance of the mutualistic pollinating wasps at the northern limit of the range of Ficus microcarpa

1. Species interactions in tightly bound ecological mutualisms often feature highly specialised species' roles in which competitive exclusion may preclude multi‐species coexistence. Among the 800 fig (Ficus) species, it was originally considered that each was pollinated by their own wasp (Agaonidae). However, recent investigations show that this ‘one‐to‐one’ rule often breaks down, as fig species regularly host multiple agaonids but in ways suggesting that competitive processes still mediate biodiversity outcomes. 2. A phenological survey was conducted of the fig–fig wasp pair, Ficus microcarpa and its associated pollinating wasp, alongside its sister species, the cheating wasp, in Xishuangbanna, China. 3. Reproductive output underwent extreme seasonal variation. Seed and pollinator production fell markedly during cooler, drier months, although high levels of fig production continued. However, this resource was predominantly utilised by the cheater species, which offers no pollination services. Pollinators and cheaters rarely co‐occur, suggesting that temporal coexistence is constrained by competition for access to figs. 4. The overall findings indicate periodic rearrangements of mutualism dynamics, probably resulting from a strongly seasonal environment. Sympatric co‐occurrence may result from a window of opportunity for a functionally divergent agaonid, potentially due to constraints on the main pollinator in adapting to variable year‐round conditions that prevent competitive exclusion.     

Different Stimuli Reduce Attraction to Pollinators in Male and Female Figs in the Dioecious Fig Ficus hispida

Fig trees ( Ficus ) and their obligate pollinating wasps (Hymenoptera, Chalcidoidea, Agaonidae) are a classic example of a coevolved mutualism. Pollinating wasps are attracted to figs only when figs are receptive. It has been shown that figs will lose their attraction to pollinators sooner in monoecious and male dioecious figs when multiple pollinators have entered the enclosed inflorescence. However, little is known about the nature of the stimulus inducing the loss of attraction. By conducting experiments on the functionally dioecious fig, Ficus hispida , we show that (1) different stimuli induce the loss of attraction in each sex, pollination in female figs, and oviposition in male figs; and (2) foundress number affects the loss of attraction in both sexes only when the prerequisites ( i.e ., pollination in female figs and oviposition in male figs) have been satisfied. In general, the more foundresses that enter, the earlier the fig will lose its receptivity. We argue that the stimuli in male and female figs are adaptations to the fulfillment of its respective reproduction.     

Sky islands as foci for divergence of fig trees and their pollinators in southwest China

The dynamics of populations and their divergence over time have shaped current levels of biodiversity and in the case of the “sky islands” of mountainous southwest (SW) China have resulted in an area of exceptional botanical diversity. Ficus tikoua is a prostrate fig tree subendemic to the area that displays unique intraspecific diversity, producing figs typical of different pollination modes in different parts of its range. By combining climate models, genetic variation in populations of the tree's obligate fig wasp pollinators and distributions of the different plant phenotypes, we examined how this unusual situation may have developed. We identified three genetically distinct groups of a single Ceratosolen pollinator species that have largely parapatric distributions. The complex topography of the region contributed to genetic divergence among the pollinators by facilitating geographical isolation and providing refugia. Migration along elevations in response to climate oscillations further enhanced genetic differentiation of the three pollinator groups. Their distributions loosely correspond to the distributions of the functionally significant morphological differences in the male figs of their host plants, but postglacial expansion of one group has not been matched by spread of its associated plant phenotype, possibly due to a major river barrier. The results highlight how interplay between the complex topography of the “sky island” complex and climate change has shaped intraspecies differentiation and relationships between the plant and its pollinator. Similar processes may explain the exceptional botanical diversity of SW China.     

Figs (Ficus spp.) and fig wasps (Chalcidoidea, Agaonidae): hypotheses for an ancient symbiosis

Figs and their pollinating fig wasps are dependent on one another for propagation of their own kinds. The wasps reproduce by ovipositing through the styles of female flowers within the closed fig receptacles (syconia). About half of the female flowers within the syconia of monoecious figs have styles which are longer than the ovipositors of the wasp, and they will therefore produce seeds rather than wasp larvae. Since a longer ovipositor would enable a wasp to reach more ovules and deposit more eggs, the question arises at to why longer ovipositors have not evolved.
In an attempt to answer this question, four seemingly plausible hypotheses are examined but each is shown to be problematical in some way. Consideration is then given to a fifth hypothesis which proposes that ovipositor length is constrained by abortion of syconia with relatively few seed embryos and many agaonid larvae. It is argued first that this pattern of abortion will be selected during a sustained period of heavy wasp infestation because seeds will then become scarce relative to pollen-carrying wasps. Increased expenditure by the fig on seed production would therefore be favoured by natural selection. A greater expenditure on seeds would occur if young syconia with exceptionally heavy wasp infestations were dropped and the saved nutrients invested in syconia of a subsequent crop containing average levels of wasp larvae and seeds. Provided that the energy and nutrient cost of dropping young syconia is small, the selective advantage to the wasp of longer ovipositors is eliminated in this way. A stable coexistence of figs and wasps is therefore possible. The paper concludes by discussing two general predictions of the abortion hypothesis, and how these may be tested.     

种间专性协同进化关系对榕属分类的影响

榕与榕小蜂的专性共生系统为人们提供了研究生物协同进化规律和进化历史的完美范例,已成为国际上研究植物与昆虫相互作用的一个热点。这也给仅根据外部形态等传统方法进行的榕属经典分类带来了极大的影响和冲击。为了进一步研究榕属的系统与进化,介绍了该属分类学研究的历史、主要分类系统和存在的问题,并对今后榕属分类的发展趋势进行展望。     

Characterization of microsatellite loci in the African fig Ficus sycomorus L. (Moraceae)

Microsatellite loci were characterized in the African fig tree Ficus sycomorus in order to investigate patterns of pollination and gene flow in this species. The loci characterized included new loci isolated from F. sycomorus and a single locus originally developed in Ficus carica. In total 12 loci were polymorphic when tested in between eight and 79 Namibian F. sycomorus individuals. Three of the new F. sycomorus loci were found to be polymorphic in cultivars of the edible fig F. carica suggesting a selection of these loci will be useful for population studies in other fig species.     

Drastic post‐LGM expansion and lack of historical genetic structure of a subtropical fig‐pollinating wasp (Ceratosolen sp. 1) of Ficus septica in Taiwan

The climatic oscillations of the last glacial period have had profound influences on the demography and levels of genetic diversity of extant species. Molecular evidence of glacial effects on temperate species has been well documented, whereas little is known regarding that on subtropical species. Here we present analyses based on partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene (1052 bp) and genotypes at 15 microsatellite loci to investigate the historical demography, population structure and ongoing gene flow of an undescribed fig‐pollinating wasp (Ceratosolen sp. 1) of Ficus septica in subtropical Taiwan. Reconstructed historical demography based on the coalescent tree of COI sequences suggests that C. sp. 1 has undergone a drastic population expansion which was tightly coupled with climatic changes since the last glacial maximum (LGM). The magnitude of the population size change was approximately 500‐fold, indicating that the population of this wasp and its host was likely highly compressed during the last glacial period. The lack of significant population differentiation (F_ST < 0.02, for all pairwise F_ST values) may be due to rapid postglacial expansion facilitated by long‐distance dispersal, although a low frequency of first‐generation migrants was detected. Our results clearly demonstrate how recent climatic changes since the LGM and dispersal ability have jointly shaped the genetic composition of a subtropical fig‐pollinating wasp.     

Conidarnes,a new oriental genus of Sycophaginae (Hymenoptera,Agaonidae) associated with Ficus section Conosycea (Moraceae)

The sycophagines are strictly associated with two subgenera of Ficus L. (Moraceae), namely Sycomorus and Urostigma. They mostly oviposit through the fig wall and lay their eggs within the fig flowers, being either gall-makers or parasitoids of other fig wasps. In this contribution, a new genus of Sycophaginae, Conidarnes Farache & Rasplus, gen. n., is described with seven new species: Conidarnes achterbergi Farache & Rasplus, sp. n.; Conidarnes bergi Farache & Rasplus, sp. n.; Conidarnes laevis Farache & Rasplus, sp. n.; Conidarnes santineloi Farache & Rasplus, sp. n.; Conidarnes subtectae Farache & Rasplus, sp. n.; Conidarnes sulcata Farache & Rasplus, sp. n.; and Conidarnes sumatranae Farache & Rasplus, sp. n. Illustrations, morphological diagnoses, dichotomous keys and multi-entry online keys to species are provided. Conidarnes species strictly occur in the oriental region, and their distribution does not overlap with the distribution of the two other genera belonging to the same clade. Due to their relative rarity, we encourage extensive sampling of Conosycea figs to improve our knowledge of the genus.     

Phylogeography of the freshwater red alga B atrachospermum viride‐brasiliense (Rhodophyta,Batrachospermales)

Phylogeography of B atrachospermum viride‐brasiliense was investigated using two mitochondrial regions: the cox2‐3 spacer and the barcode region of cox1 gene. Eighty‐seven individuals were analyzed from nine stream segments throughout its distribution in Brazil. Ten cox2‐3 spacer and nine cox1 haplotypes were observed among the individuals studied (87 vs. 43, respectively). Divergences among haplotypes were relatively low (≤2.4% for cox2‐3 and ≤1.8% for cox1). Most locations have a single haplotype, whereas only two locations had two haplotypes for both markers. The haplotype network for cox2‐3 showed a phylogeographic trend from the south towards the southeast with haplotypes from the southeast more closely related. For cox1 a trend from the southeast spreading towards the south and north was revealed, with the southern haplotypes more closely associated. Results clearly indicated that B . viride‐brasiliense represents a single species and the phylogeographic pattern consisted of a closely connected group of haplotypes from southern and southeastern Brazil. Levels of intra‐ and inter‐population variation were similar for the two markers with slightly higher values for cox2‐3. The trend observed in this study is similar to that in other members of Batrachospermales with little variation within a stream segment (one or two haplotypes) and more distant haplotypes showing higher divergences. This pattern could be attributed to the fact that colonization of a site might be rare by a single event with subsequent proliferation of the population. The geographic distribution of B . viride‐brasiliense was interpreted according to the biogeographic models proposed for South America being limited to three morpho‐climatic domains or biogeographic provinces: tropical Atlantic rainforest, sub‐tropical rainforest and cerrado (Brazilian savannah).     

Differences in Anti‐Herbivore Defenses in Non‐Myrmecophyte and Myrmecophyte Cecropia Trees

Little is known about antiherbivore defenses in non‐myrmecophyte Cecropia trees. We compare two non‐myrmecophyte Cecropia—Cecropia sciadophylla and Cecropia tacuna—with Cecropia membranacea, a myrmecophyte. High levels of chemical defenses in young leaves and physical toughness of mature leaves compensate for the absence of mutualistic ants in C. sciadophylla. Some C. tacuna trees produce trichilia and Müllerian bodies suggesting it has lost a mutualism with ants.     

Schistonchus africanus n. sp. (Aphelenchida: Aphelenchoididae) Associated with Ficus thonningii (Moraceae) and its Pollinator Wasp Elisabethiella stuckenbergi (Chalcidoidea: Agaonidae)

Syconia ("figs") from Ficus thonningii and adults of its pollinator wasp Elisabethiella stuckenbergi were dissected to elucidate their association with a new species of Schistonchus (Aphelenchoididae). Schistonchus africanus n. sp. is characterized by a short stylet (13-16 μm long); position of the excretory pore opening in both sexes at a level just behind the stylet knobs; and short post-uterine branch, one body-width long. Schistonchus africanus n. sp. parasitizes F. thonningii florets and is transported by the winged females of E. stuckenbergi. Juveniles, females, and males of the nematode were found in the female and male fig florets and in the abdomen of the vector. Nematode populations extracted from female wasps or fig floret tissues did not differ in their morphology. No association was observed with the wingless males of the pollinator wasp.