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Stephen G Compton - One of the best experts on this subject based on the ideXlab platform.
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host parasitoid relationships within Figs of an invasive Fig tree a Fig Wasp community structured by gall size
Insect Conservation and Diversity, 2018Co-Authors: Yan-qiong Peng, Stephen G Compton, R. J. Quinnell, Xiaoyong Chen, Yan Chen, Melanie J Hatcher, Lillian Jennifer Rodriguez, Hui Yu, Ao OuyangAbstract:1. Revealing the host specificity of the predators/parasitoids of invasive species is a prerequisite when assessing the suitability of biocontrol agents, while the host ranges of top predators are likely to vary among communities comprising different species. 2. Ficus microcarpa is a native plant in Asia and Australasia and has invaded in sometropical and subtropical areas. Besides its species‐specific pollinator, its Figs also support many ovule‐galling and parasitoid non‐pollinating Fig Wasps. 3. Here, based on a global collection of Fig Wasps associated with F. microcarpa Figs, we used path analysis, supplemented by within‐Fig spatial distributions and natal gall sizes to reveal food web structure of its associated Fig Wasps and the factors forming host ranges of parasitoids. 4. The Fig Wasp community was species‐rich, and parasitoids were far rarer in the plant's introduced range. Parasitoids exhibited some host specificity, and four specific natural enemies of the plant's pollinator were identified with various intensities of effects on pollinator abundance. Parasitoid host ranges were consistent in both ranges of the plant, and mainly restricted by the size and the locations of host galls. No parasitoids were found associated with a unique seed predator. 5. Our results showed how a large number of Fig Wasp species partition one host Fig tree's Figs and identified the species that have potential to control the sexual reproduction of F. microcarpa.
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first record of a non pollinating Fig Wasp hymenoptera sycophaginae from dominican amber with estimation of the size of its host Figs
Journal of Natural History, 2016Co-Authors: Fernando Henrique Antoniolli Farache, Rodrigo Augusto Santinelo Pereira, Jeanyves Rasplus, Dany Azar, Stephen G ComptonAbstract:ABSTRACTFig trees and their pollinating Fig Wasps arose about 75 million years ago in the Cretaceous period. Several other groups of chalcid Wasps also utilize Figs for larval development, including sycophagines, the putative sister group to pollinating Fig Wasps. Whereas stone and amber fossil pollinators are known, no fossils representing non-pollinating Fig Wasp groups have been confirmed previously. Here, we describe the first Sycophaginae from the c.15–20 Ma Dominican amber, Idarnes thanatos sp. nov. Farache, Rasplus, Pereira and Compton, and discuss its relationships within the Idarnes carme species group. Additionally, we use linear regression to compare body size, ovipositor sheaths length, and host Fig size data from extant Idarnes species to estimate the size of its host Figs. Idarnes thanatos was most likely associated with small to medium sized Figs (diameter ≤1.0 cm), that were likely to have been dispersed by birds and primates. The discovery of this close relative of extant non-pollinating ...
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spatial heterogeneity and host repression in Fig Fig Wasp mutualism
Science China-life Sciences, 2015Co-Authors: Ruiwu Wang, Stephen G Compton, Chun ChenAbstract:It is generally believed that physical heterogeneity in common resource or evolutionary restraint can sufficiently prevent direct conflict between host and symbionts in mutualism systems. Our data on Fig/Fig Wasp reciprocal mutualism (Ficus racemosa), however, show that structural barriers of female flowers or genetic constraints of pollinators previously hypothesized exist, but cannot sufficiently maintain the mutualism stability. The results show that a positive relationship between seed and Wasp production could be maintained in warm season, which might be because of density dependence restraint among foundresses and their low oviposition and pollination efficiency, keeping common resource (female flowers) utilization unsaturated. Whilst, a negative correlation between Wasp offspring and viable seed production was also observed in cold season, which might be that the increased oviposition and pollination efficiency maximized the common resource utilization. The fitness trade-off between Fig and pollinator Wasps is greatly affected by environmental or ecological variations. The local stability might result from temporal low exploitation efficiency of pollinators together with interference competition among pollinators. We suggest that host repression through the active regulation of bract closure, which can create interference competition among the foundresses and prevent extra more foundresses sequential entry in fruit cavities, would help the Figs avoiding the cost of over-exploitation. This essentially takes the same role as sanctioning of cheating or competitive behaviors.
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complementary fruiting phenologies facilitate sharing of one pollinator Fig Wasp by two Fig trees
Journal of Plant Ecology, 2015Co-Authors: Da-rong Yang, Yan-qiong Peng, Stephen G ComptonAbstract:Aims Most pollinator Fig Wasps are host plant specific, with each species only breeding in the Figs of one Fig tree species, but increasing numbers of species are known to be pollinated by more than one Fig Wasp, and in rare instances host switching can result in Ficus species sharing pollinators. In this study, we examined factors facilitating observed host switching at Xishuangbanna in Southwestern (SW) China, where Ficus squamosa is at the northern edge of its range and lacks the Fig Wasps that pollinate it elsewhere, and its Figs are colonized by a Ceratosolen pollinator that routinely breeds in Figs of F. heterostyla. Methods We recorded the habitat preferences of F. squamosa and F. heterostyla at Xishuangbanna, and compared characteristics such as Fig size, location and colour at receptive phase. Furthermore, the vegetative and reproductive phenologies in the populations of F. squamosa and F. heterostyla were recorded weekly at Xishuangbanna Tropical Botanical Garden for 1 year. Important Findings Ficus squamosa is a shrub found near fast-flowing rivers, F. heterostyla is a small tree of disturbed forest edges. Although preferring different habitats, they can be found growing close together. Both species have Figs located at or near ground level, but they differ in size when pollinated. Fig production in F. squamosa was concentrated in the colder months. F. heterostyla produced more Figs in summer but had some throughout the year. The absence of its normal pollinators, in combination with similarly located Figs and partially complementary fruiting patterns appear to have facilitated colonization of F. squamosa by the routine pollinator of F. heterostyla. The Figs probably also share similar attractant volatiles. This host switching suggests one mechanism whereby Fig trees can acquire new pollinators and emphasizes the likely significance of edges of ranges in the genesis of novel Fig tree-Fig Wasp relationships.
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first record of an apparently rare Fig Wasp feeding strategy obligate seed predation
Ecological Entomology, 2014Co-Authors: Rong Wang, Yan-qiong Peng, Stephen G Compton, Lien-siang Chou, Louise J Barwell, Hui Yu, Ashley Matthews, Joanne Ratcliffe, Huiwen YangAbstract:1. Fig trees require host-specific agaonid Fig Wasps for pollination, but their Figs also support numerous non-pollinating Fig Wasps (NPFW) that gall Fig tissues or develop as parasitoids, 2. Ficus microcarpa L. is widely naturalised outside its native range and the most invasive Fig tree species. Seed predators are widely used for the biological control of invasive plants, but 110 obligate seed predatory (as opposed to ovule or Fig wall galling) NPFW have been recorded previously from any Fig trees. 3. Philotrypesis NPFW are usually regarded as parasitoids or inquilines' (parasitoids that also eat plant material) of pollinator Fig Wasps, but the present study provides evidence that Philotrypesis taiwanensis, a NPFW associated with E microcarpa, is an obligate seed predator: (i) adults emerge from seeds of typical appearance, with a surrounding elaiosome; (ii) it shows no preference for Figs occupied by Fig Wasp species, other than the pollinator; (iii) it only develops in Figs that contain pollinated ovules, avoiding Figs occupied by an agaonid that fails to pollinate; (iv) larvae are distributed in layers where seeds are concentrated and (v) it has a negative impact on seed but not pollinator offspring numbers, 4. Philotrypesis is a large genus, and further species are likely to be seed predators.
Dawei Huang - One of the best experts on this subject based on the ideXlab platform.
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description of two new species from china in a new species group of the Fig Wasp genus sycophaga westwood hymenoptera chalcidoidea agaonidae sycophaginae
Zootaxa, 2016Co-Authors: Zi Li, Dawei HuangAbstract:A new species group, the brevis -group, is established for two new species of the Fig Wasp genus Sycophaga Westwood (Hymenoptera: Agaonidae) reared from the monoecious Fig tree Ficus orthoneura (Moraceae, Ficus , subgenus Urostigma ) in China. The two new species, S. brevis n. sp. and S. diutius n. sp. are described and illustrated, supplemented by COI sequence data. In contrast with two other species groups newly recognized in Sycophaga, the explorator -group for species previously classified in Apocryptophagus Ashmead and the sycomori -group for other species previously classified in Sycophaga , the brevis -group is uniquely defined by the long pronotum of females and a Ficus host within the subgenus Urostigma .
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large proportion of genes in one cryptic wo prophage genome are actively and sex specifically transcribed in a Fig Wasp species
BMC Genomics, 2014Co-Authors: Guanhong Wang, Jinhua Xiao, Dawei HuangAbstract:Cryptic prophages are genetically defective in their induction and propagation, and are simply regarded as genetic remnants. There are several putative cryptic WO prophages in the sequenced Wolbachia genomes. Whether they are lytic is unclear and their functions are poorly understood. Only three open reading frames (ORFs) in cryptic WO prophages have been reported to be actively transcribed. In this study, we comprehensively examined the transcription of the only cryptic WO prophage (WOSol) in a Wolbachia strain that infects a Fig Wasp, Ceratosolen solmsi (Agaonidae, Chalcidoidea). By analyzing the transcriptions of all the ORFs of WOSol in both sexes of C. solmsi, using qualitative and quantitative methods, we demonstrated that i) a high percentage of ORFs are actively transcribed (59%, 17/29); ii) the expression of these ORFs is highly sex-specific, with a strong male bias (three in females and 15 in males); iii) an ank (ankyrin-domain-containing) gene actively transcribed in both Wasp sexes is more highly expressed in males. A large proportion of the genes in the cryptic WO prophage WOSol are expressed, which overturns the concept that cryptic prophages are simply genetically defective. The highly sex-specific expression patterns of these genes in the host suggest that they play important roles in Wolbachia biology and its reproductive manipulation of its insect host, particularly through the males.
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evidence for the circadian gene period as a proximate mechanism of protandry in a pollinating Fig Wasp
Biology Letters, 2014Co-Authors: Haifeng Gu, Jinhua Xiao, Derek W Dunn, Dawei Huang, Bo WangAbstract:Protandry in insects is the tendency for adult males to emerge before females and usually results from intra-sexual selection. However, the genetic basis of this common phenomenon is poorly understood. Pollinating Fig Wasp (Agaonidae) larvae develop in galled flowers within the enclosed inflorescences (‘Figs’) of Fig trees. Upon emergence, males locate and mate with the still galled females. After mating, males release females from their galls to enable dispersal. Females cannot exit galls or disperse from a Fig without male assistance. We sampled male and female Ceratosolen solmsi (the pollinator of Ficus hispida) every 3 h over a 24 h emergence period, and then measured the expression of five circadian genes: period (per), clock (clk), cycle (cyc), pigment-dispersing factor (pdf) and clockwork orange (cwo). We found significant male-biased sexual dimorphism in the expression of all five genes. per showed the greatest divergence between the sexes and was the only gene rhythmically expressed. Expression of per correlated closely with emergence rates at specific time intervals in both male and female Wasps. We suggest that this rhythmical expression of per may be a proximate mechanism of protandry in this species.
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high efficiency thermal asymmetric interlaced pcr hitail pcr for determination of a highly degenerated prophage wo genome in a wolbachia strain infecting a Fig Wasp species
Applied and Environmental Microbiology, 2013Co-Authors: Guanhong Wang, Jinhua Xiao, Dawei Huang, Zi Li, Tuanlin Xiong, Robert W MurphyAbstract:ABSTRACT Temperate bacteriophage WO is a model system for studying tripartite interactions among viruses, bacteria, and eukaryotes, especially investigations of the genomic stability of obligate intracellular bacteria. Few WO genomes exist because of the difficulty in isolating viral DNA from eukaryotic hosts, and most reports are by-products of Wolbachia sequencing. Only one partial genome of a WO phage has been determined directly from isolated particles. We determine the complete genome sequence of prophage WO (WOSol) in Wolbachia strain w Sol, which infects the Fig Wasp Ceratosolen solmsi (Hymenoptera: Chalcidoidea), by high-efficiency thermal asymmetric interlaced PCR. The genome of WOSol is highly degenerated and disrupted by a large region (14,267 bp) from Wolbachia. Consistent with previous molecular studies of multiple WO genomes, the genome of WOSol appears to have evolved by single nucleotide mutations and recombinations.
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pollinating Fig Wasp ceratosolen solmsi adjusts the offspring sex ratio to other foundresses
Insect Science, 2013Co-Authors: Haoyuan Hu, Dawei Huang, Zhongzheng Chen, Zifeng Jiang, Yueguan FuAbstract:: Local mate competition theory predicts that offspring sex ratio in pollinating Fig Wasps is female-biased when there is only one foundress, and increased foundress density results in increased offspring sex ratio. Information of other foundresses and clutch size have been suggested to be the main proximate explanations for sex ratio adjustment under local mate competition. Our focus was to show the mechanism of sex ratio adjustment in a pollinating Fig Wasp, Ceratosolen solmsi Mayr, an obligate pollinator of the functionally dioecious Fig, Ficus hispida Linn., with controlled experiments in the field. First, we obtained offspring from one pollinator and offspring at different oviposition sequences, and found that offspring sex ratio decreased with clutch size, and pollinators produced most of their male offspring at the start of bouts, followed by mostly females. Second, we found that offspring sex ratio increased with foundress density, and pollinators did adjust their offspring sex ratio to other females in the oviposition patches. We suggest that when oviposition sites are not limited, pollinators will mainly adjust their offspring sex ratio to other foundresses independent of clutch size changes, whereas adjusting clutch size may be used to adjust sex ratio when oviposition sites are limited.
James M Cook - One of the best experts on this subject based on the ideXlab platform.
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low coverage genomic data resolve the population divergence and gene flow history of an australian rain forest Fig Wasp
bioRxiv, 2020Co-Authors: Lisa Cooper, James M Cook, Lynsey Bunnefeld, Jack Hearn, Konrad Lohse, Graham N StoneAbstract:Population divergence and gene flow are key processes in evolution and ecology. Model-based analysis of genome-wide datasets allows discrimination between alternative scenarios for these processes even in non-model taxa. We used two complementary approaches (one based on the blockwise site frequency spectrum (bSFS), the second on the Pairwise Sequentially Markovian Coalescent (PSMC)) to infer the divergence history of a Fig Wasp, Pleistodontes nigriventris. Pleistodontes nigriventris and its Fig tree mutualist Ficus watkinsiana are restricted to rain forest patches along the eastern coast of Australia, and are separated into northern and southern populations by two dry forest corridors (the Burdekin and St. Lawrence Gaps). We generated whole genome sequence data for two haploid males per population and used the bSFS approach to infer the timing of divergence between northern and southern populations of P. nigriventris, and to discriminate between alternative isolation with migration (IM) and instantaneous admixture (ADM) models of post divergence gene flow. Pleistodontes nigriventris has low genetic diversity (π = 0.0008), to our knowledge one of the lowest estimates reported for a sexually reproducing arthropod. We find strongest support for an ADM model in which the two populations diverged ca. 196kya in the late Pleistocene, with almost 25% of northern lineages introduced from the south during an admixture event ca. 57kya. This divergence history is highly concordant with individual population demographies inferred from each pair of haploid males using PSMC. Our analysis illustrates the inferences possible with genome-level data for small population samples of tiny, non-model organisms and adds to a growing body of knowledge on the population structure of Australian rain forest taxa.
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chemical camouflage a key process in shaping an ant treehopper and Fig Fig Wasp mutualistic network
Scientific Reports, 2018Co-Authors: Bo Wang, James M Cook, Derek W Dunn, Da-rong Yang, Min Lu, Ruiwu WangAbstract:Different types of mutualisms may interact, co-evolve and form complex networks of interdependences, but how species interact in networks of a mutualistic community and maintain its stability remains unclear. In a mutualistic network between treehoppers-weaver ants and Fig-pollinating Wasps, we found that the cuticular hydrocarbons of the treehoppers are more similar to the surface chemical profiles of Fig inflorescence branches (FIB) than the cuticular hydrocarbons of the Fig Wasps. Behavioral assays showed that the cuticular hydrocarbons from both treehoppers and FIBs reduce the propensity of weaver ants to attack treehoppers even in the absence of honeydew rewards, suggesting that chemical camouflage helps enforce the mutualism between weaver ants and treehoppers. High levels of weaver ant and treehopper abundances help maintain the dominance of pollinating Fig Wasps in the Fig Wasp community and also increase Fig seed production, as a result of discriminative predation and disturbance by weaver ants of ovipositing non-pollinating Fig Wasps (NPFWs). Ants therefore help preserve this Fig-pollinating Wasp mutualism from over exploitation by NPFWs. Our results imply that in this mutualistic network chemical camouflage plays a decisive role in regulating the behavior of a key species and indirectly shaping the architecture of complex arthropod-plant interactions.
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cryptic diversity in a Fig Wasp community morphologically differentiated species are sympatric but cryptic species are parapatric
Molecular Ecology, 2017Co-Authors: James M Cook, Clive T DarwellAbstract:: A key debate in ecology centres on the relative importance of niche and neutral processes in determining patterns of community assembly with particular focus on whether ecologically similar species with similar functional traits are able to coexist. Meanwhile, molecular studies are increasingly revealing morphologically indistinguishable cryptic species with presumably similar ecological roles. Determining the geographic distribution of such cryptic species provides opportunities to contrast predictions of niche vs. neutral models. Discovery of sympatric cryptic species increases alpha diversity and supports neutral models, while documentation of allopatric/parapatric cryptic species increases beta diversity and supports niche models. We tested these predictions using morphological and molecular data, coupled with environmental niche modelling analyses, of a Fig Wasp community along its 2700-km latitudinal range. Molecular methods increased previous species diversity estimates from eight to eleven species, revealing morphologically cryptic species in each of the four Wasp genera studied. Congeneric species pairs that were differentiated by a key morphological functional trait (ovipositor length) coexisted sympatrically over large areas. In contrast, morphologically similar species, with similar ovipositor lengths, typically showed parapatric ranges with very little overlap. Despite parapatric ranges, environmental niche models of cryptic congeneric pairs indicate large regions of potential sympatry, suggesting that competitive processes are important in determining the distributions of ecologically similar species. Niche processes appear to structure this insect community, and cryptic diversity may typically contribute mostly to beta rather than alpha diversity.
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one step ahead a parasitoid disperses farther and forms a wider geographic population than its Fig Wasp host
Molecular Ecology, 2016Co-Authors: Timothy L Sutton, Markus Riegler, James M CookAbstract:: The structure of populations across landscapes influences the dynamics of their interactions with other species. Understanding the geographic structure of populations can thus shed light on the potential for interacting species to co-evolve. Host-parasitoid interactions are widespread in nature and also represent a significant force in the evolution of plant-insect interactions. However, there have been few comparisons of population structure between an insect host and its parasitoid. We used microsatellite markers to analyse the population genetic structure of Pleistodontes imperialis sp. 1, a Fig-pollinating Wasp of Port Jackson Fig (Ficus rubiginosa), and its main parasitoid, Sycoscapter sp. A, in eastern Australia. Besides exploring this host-parasitoid system, our study also constitutes, to our knowledge, the first study of population structure in a nonpollinating Fig Wasp species. We collected matched samples of pollinators and parasitoids at several sites in two regions separated by up to 2000 km. We found that pollinators occupying the two regions represent distinct populations, but, in contrast, parasitoids formed a single population across the wide geographic range sampled. We observed genetic isolation by distance for each species, but found consistently lower FST and RST values between sites for parasitoids compared with pollinators. Previous studies have indicated that pollinators of monoecious Figs can disperse over very long distances, and we provide the first genetic evidence that their parasitoids may disperse as far, if not farther. The contrasting geographic population structures of host and parasitoid highlight the potential for geographic mosaics in this important symbiotic system.
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a trophic cascade induced by predatory ants in a Fig Fig Wasp mutualism
Journal of Animal Ecology, 2014Co-Authors: Xiangzong Geng, James M Cook, Bo Wang, Ruiwu WangAbstract:1. A trophic cascade occurs when predators directly decrease the densities, or change the behaviour, of herbivores and thus indirectly increase plant productivity. The predator-herbivore-plant context is well known, but some predators attack species beneficial to plants (e. g. pollinators) and/or enemies of herbivores (e.g. parasites), and their role in the dynamics of mutualisms remains largely unexplored. 2. We surveyed the predatory ant species and studied predation by the dominant ant species, the weaver ant Oecophylla smaragdina, associated with the Fig tree Ficus racemosa in southwest China. We then tested the effects of weaver ants on the oviposition behaviour of pollinating and non-pollinating Fig Wasps in an ant-exclusion experiment. The effects of weaver ants on Fig Wasp community structure and Fig seed production were then compared between trees with and without O. smaragdina. 3. Oecophylla smaragdina captured more non-pollinating Wasps (Platyneura mayri) than pollinators as the insects arrived to lay eggs. When ants were excluded, more non-pollinators laid eggs into Figs and fewer pollinators entered Figs. Furthermore, trees with O. smaragdina produced more pollinator offspring and fewer non-pollinator offspring, shifting the community structure significantly. In addition, F. racemosa produced significantly more seeds on trees inhabited by weaver ants. 4. Oecophylla smaragdina predation reverses the dominance of the two commonest Wasp species at the egg-laying stage and favours the pollinators. This behavioural pattern is mirrored by Wasp offspring production, with pollinators' offspring dominating Figs produced by trees inhabited by weaver ants, and offspring of the non-pollinator P. mayri most abundant in Figs on trees inhabited by other ants. 5. Overall, our results suggest that predation by weaver ants limits the success of the non-pollinating P. mayri and therefore indirectly benefits the mutualism by increasing the reproductive success of both the pollinators and the plant. Predation is thus a key functional factor that can shape the community structure of a pollinator-plant mutualistic system.
Yan-qiong Peng - One of the best experts on this subject based on the ideXlab platform.
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Fig and Fig Wasp biology : A perspective from the East
Symbiosis, 2020Co-Authors: Rhett D. Harrison, Nina Rønsted, Yan-qiong PengAbstract:The papers in this volume are the result of a meeting of Fig and Fig Wasp biologists held in China, July 2006. Here we provide an overview of current themes in Fig-Fig Wasp research and introduce the papers in this volume. Figs are pollinated by tiny, highly specific Wasps whose larvae feed on a proportion of the flowers they pollinate. Other symbionts, including a diversity of non-pollinating Wasps and vertebrate fruit eaters, exploit or otherwise depend on this obligate mutualistic interaction. Recently it was found that a substantial number of Fig species harbour more than one species of pollinating Wasp. This has lead to renewed interest in the question of specificity and its co-evolutionary implications. There has also been a substantial increase in the interest in Fig and Fig Wasp biology in Asia, not least in China where our meeting was held. Directly following from this is an increased interest in dioecious Figs, which are predominantly Asian. Dioecious Figs offer a very different perspective on the stability of the Fig-Fig pollinator interaction to the better studied monoecious Figs. They have also radiated into a remarkable diversity of ecological niches and, therefore, promise to reveal how Fig-Fig Wasp interactions have responded to a variety of different ecological conditions. The study of non-pollinating Fig Wasp communities, which are every bit as interesting as the pollinating Wasps, has been hampered by difficulties in determining their life-histories. A number of the papers presented here pioneer new methods to address these difficulties, and hence promise to prise open this field. Fig and Fig Wasp biology appears on the cusp of rapid developments on a number of fronts, and hence Fig-Fig Wasp biologists can look forward with excitement to the coming years.
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The reproductive strategies of non-pollinating Fig Wasps in Ficus cyrtophylla and their effects on the Fig-Wasp mutualism
2020Co-Authors: Da-rong Yang, Yan-qiong PengAbstract:Through extensive collecting, behavioral observation and test of obstructing Fig Wasps from entering Figs, the community structure of Fig Wasps, the reproductive strategies of non-pollinating Fig Wasps (NPFW) and the effects of non-pollinating Fig Wasps on the Fig-Wasp mutualism of Ficus cyrtophylla, an understory Fig species in the tropical rain forest of Xishuangbanna, were studied. Except the obligate pollinator-Blastophaga sp. for F. cyrtophylla, there were three non-pollinating Fig Wasp species in its syconia, i.e., Platyneura sp., Philotrypesis sp. and Sycoscapter sp. In the Fig Wasp community, Blastophaga sp., as the dominant species, accounted for 92.21% of the total Fig Wasps, while Sycoscapter sp. accounted for only 5.78%, Philotrypesis sp. 1.84% and Platyneura sp. 0.17% of the total Fig Wasps. Sycoscapter sp. was the primary non-pollinating Fig Wasp. All these non-pollinators oviposited outside the Figs, and they produced their offsprings through co-inhabiting and competing with pollinators for reproductive sites or food resources. Platyneura sp. was the gall-maker while Philotrypesis sp. and Sycoscapter sp. were both inquilines. If no pollinators entered the Figs, all the non-pollinators would fail to produce their offsprings. The non-pollinators performed some significantly negative effects on the pollinator population size and the number of female pollinators, but not on the number of male pollinating Fig Wasps, and thus resulted in a significant increase of the ratio of males to the total number of the pollinators. These results show that non-pollinators usually prefer the galls of female pollinators to the galls of male pollinating Fig Wasps when they oviposit. Because the female pollinators are the only vectors for Figs, the non-pollinators may negatively affect the stable existence and development of the Fig-Wasp mutualism.
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Are nematodes costly to Fig tree–Fig Wasp mutualists?
Entomologia Experimentalis Et Applicata, 2019Co-Authors: Baige Miao, Bo Wang, Simon T Segar, Yongsan Zeng, Yan-qiong PengAbstract:Most mutualisms are exploited by parasites, which must strike an evolutionary balance between virulence and long‐term persistence. Fig‐associated nematodes, living inside Figs and dispersed by Fig Wasps, are thought to be exploiters of the Fig–Fig Wasp mutualism. The life history of nematodes is synchronized with the Fig development and adapted to particular developmental characteristics of Figs. We expect host breeding systems (monoecious vs. gynodioecious Figs) and seasonality to be central to this adaptation. However, the details of the adaptation are largely unknown. Here, we conducted the first field surveys on the prevalence of nematodes from monoecious Ficus microcarpa L.f. (Moraceae), gynodioecious Ficus hispida L.f., and their pollinating Fig Wasps in two seasons and two developmental stages of Figs in Xishuangbanna, China. We followed this up by quantifying the effects of nematodes on fitness‐related traits on Fig Wasps (e.g., egg loads, pollen grains, and longevity) and Fig trees (seed production) in gynodioecious F. hispida. The magnitude of nematode infection was compared between pre‐ and post‐dispersal pollinators to quantify the probability of nematodes being transported to new hosts. Our results showed that Ficophagus microcarpus (Nematoda: Aphelenchoididae) was the only nematode in F. microcarpa. In F. hispida, Martininema guangzhouensis (Nematoda: Aphelenchoididae) was the dominant nematode species, whereas Ficophagus centerae was rare. For both species of Ficus, rainy season and inter‐floral Figs had higher rates of nematode infection than the dry‐hot season and receptive Figs. Nematodes did not affect the number of pollen grains or egg loads of female Wasps. We did not detect a correlation between seed production and nematode infection. However, carrying nematodes reduced the lifespan and dispersal ability of pollinator Wasps, indicating higher rates of post‐emergence mortality in infected Fig Wasps. Severely infected Fig Wasps were likely ‘filtered out’, preventing the overexploitation of Figs by Wasps and stabilizing the interaction over evolutionary time.
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are nematodes costly to Fig tree Fig Wasp mutualists
Entomologia Experimentalis Et Applicata, 2019Co-Authors: Bo Wang, Yan-qiong Peng, Simon T Segar, Baige Miao, Yongsan ZengAbstract:Most mutualisms are exploited by parasites, which must strike an evolutionary balance between virulence and long‐term persistence. Fig‐associated nematodes, living inside Figs and dispersed by Fig Wasps, are thought to be exploiters of the Fig–Fig Wasp mutualism. The life history of nematodes is synchronized with the Fig development and adapted to particular developmental characteristics of Figs. We expect host breeding systems (monoecious vs. gynodioecious Figs) and seasonality to be central to this adaptation. However, the details of the adaptation are largely unknown. Here, we conducted the first field surveys on the prevalence of nematodes from monoecious Ficus microcarpa L.f. (Moraceae), gynodioecious Ficus hispida L.f., and their pollinating Fig Wasps in two seasons and two developmental stages of Figs in Xishuangbanna, China. We followed this up by quantifying the effects of nematodes on fitness‐related traits on Fig Wasps (e.g., egg loads, pollen grains, and longevity) and Fig trees (seed production) in gynodioecious F. hispida. The magnitude of nematode infection was compared between pre‐ and post‐dispersal pollinators to quantify the probability of nematodes being transported to new hosts. Our results showed that Ficophagus microcarpus (Nematoda: Aphelenchoididae) was the only nematode in F. microcarpa. In F. hispida, Martininema guangzhouensis (Nematoda: Aphelenchoididae) was the dominant nematode species, whereas Ficophagus centerae was rare. For both species of Ficus, rainy season and inter‐floral Figs had higher rates of nematode infection than the dry‐hot season and receptive Figs. Nematodes did not affect the number of pollen grains or egg loads of female Wasps. We did not detect a correlation between seed production and nematode infection. However, carrying nematodes reduced the lifespan and dispersal ability of pollinator Wasps, indicating higher rates of post‐emergence mortality in infected Fig Wasps. Severely infected Fig Wasps were likely ‘filtered out’, preventing the overexploitation of Figs by Wasps and stabilizing the interaction over evolutionary time.
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host parasitoid relationships within Figs of an invasive Fig tree a Fig Wasp community structured by gall size
Insect Conservation and Diversity, 2018Co-Authors: Yan-qiong Peng, Stephen G Compton, R. J. Quinnell, Xiaoyong Chen, Yan Chen, Melanie J Hatcher, Lillian Jennifer Rodriguez, Hui Yu, Ao OuyangAbstract:1. Revealing the host specificity of the predators/parasitoids of invasive species is a prerequisite when assessing the suitability of biocontrol agents, while the host ranges of top predators are likely to vary among communities comprising different species. 2. Ficus microcarpa is a native plant in Asia and Australasia and has invaded in sometropical and subtropical areas. Besides its species‐specific pollinator, its Figs also support many ovule‐galling and parasitoid non‐pollinating Fig Wasps. 3. Here, based on a global collection of Fig Wasps associated with F. microcarpa Figs, we used path analysis, supplemented by within‐Fig spatial distributions and natal gall sizes to reveal food web structure of its associated Fig Wasps and the factors forming host ranges of parasitoids. 4. The Fig Wasp community was species‐rich, and parasitoids were far rarer in the plant's introduced range. Parasitoids exhibited some host specificity, and four specific natural enemies of the plant's pollinator were identified with various intensities of effects on pollinator abundance. Parasitoid host ranges were consistent in both ranges of the plant, and mainly restricted by the size and the locations of host galls. No parasitoids were found associated with a unique seed predator. 5. Our results showed how a large number of Fig Wasp species partition one host Fig tree's Figs and identified the species that have potential to control the sexual reproduction of F. microcarpa.
Edward Allen Herre - One of the best experts on this subject based on the ideXlab platform.
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host sanctions and pollinator cheating in the Fig tree Fig Wasp mutualism
Proceedings of The Royal Society B: Biological Sciences, 2010Co-Authors: Charlotte K Jander, Edward Allen HerreAbstract:Theory predicts that mutualisms should be vulnerable to invasion by cheaters, yet mutualistic interactions are both ancient and diverse. What prevents one partner from reaping the benefits of the interaction without paying the costs? Using field experiments and observations, we examined factors affecting mutualism stability in six Fig tree–Fig Wasp species pairs. We experimentally compared the fitness of Wasps that did or did not perform their most basic mutualistic service, pollination. We found host sanctions that reduced the fitness of non-pollinating Wasps in all derived, actively pollinated Fig species (where Wasps expend time and energy pollinating), but not in the basal, passively pollinated Fig species (where Wasps do not). We further screened natural populations of pollinators for Wasp individuals that did not carry pollen (‘cheaters’). Pollen-free Wasps occurred only in actively pollinating Wasp species, and their prevalence was negatively correlated with the sanction strength of their host species. Combined with previous studies, our findings suggest that (i) mutualisms can show coevolutionary dynamics analogous to those of ‘arms races’ in overtly antagonistic interactions; (ii) sanctions are critical for long-term mutualism stability when providing benefits to a host is costly, and (iii) there are general principles that help maintain cooperation both within and among species.
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multi locus phylogenetic analysis of neotropical Figs does not support co speciation with the pollinators the importance of systematic scale in Fig Wasp cophylogenetic studies
Symbiosis, 2008Co-Authors: Andrew P Jackson, Carlos A Machado, Nancy Robbins, Edward Allen HerreAbstract:For 18 species of Panamanian Ficus, representing both basal (Pharmacosycea; 4 spp.) and derived (Urostigma, Americana; 14 spp.) sections, we sampled multiple individuals per species and analyzed sequence data from multiple (3) genetic markers (tpi, g3pdh, ITS). In contrast to previous phylogenetic studies of Figs, this sampling design allowed us to evaluate the degree to which different alleles within loci, and different loci within individual species suggest consistent phylogenetic relationships among both distantly and closely related Figs. We found multiple instances within both tpi and g3pdh genes in which different haplotypes were not monophyletic by species. Haplotype and reconciliation analyses suggested that genetic exchange among closely related Figs is necessary to fully explain the patterns. In contrast, analyses of multiple loci from multiple individuals in the Wasps are monophyletic by species, producing a well resolved species phylogeny. Although combining Fig genetic data sets produced a resolved and robust Fig topology, no Fig phylogenies based on either combined or individual gene trees showed any significant correspondence with the Wasp tree. Recent studies have shown that many of the Fig species considered here have multiple pollinators and several share genetically indistinguishable pollinators. Together with these genetic results, it appears that a strict co-speciation model does not adequately describe the general evolutionary dynamics of the Fig/Wasp mutualism, particularly for sympatric, closely related species (within section). Importantly, these results emphasize the need to consider multiple genes, multiple individuals, and systematic scale in order to conduct and interpret robust co-phylogenetic studies of Figs and their pollinating Wasps.
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critical review of host specificity and its coevolutionary implications in the Fig Fig Wasp mutualism
Proceedings of the National Academy of Sciences of the United States of America, 2005Co-Authors: Carlos A Machado, Nancy Robbins, Thomas M P Gilbert, Edward Allen HerreAbstract:Figs (Ficus spp., Moraceae) and their pollinating Wasps (Agaonidae, Chalcidoidea) constitute perhaps the most tightly integrated pollination mutualism that is known. Figs are characterized by extraordinarily high global and local species diversity. It has been proposed that the diversification of this mutualism has occurred through strict-sense coadaptation and cospeciation between pairs of Fig and Wasp species that are associated in highly specific one-to-one relationships. However, existing studies cast doubt on the generality of this proposition. Here, we review our current knowledge of the evolutionary history of the Fig/Fig-Wasp mutualism. We critically examine the idea that codivergence between Figs and their pollinators has been dominated by strict-sense cospeciation. We present phylogenetic and population genetic data from neotropical Fig and Fig Wasp species that suggest that a more accurate model for diversification in this mutualism is that of groups of genetically well defined Wasp species coevolving with genetically less well defined (frequently hybridizing) groups of Figs. Last, we use our results to assess previously proposed hypotheses on models of speciation in this mutualism.
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inbreeding and population structure in two pairs of cryptic Fig Wasp species
Molecular Ecology, 2004Co-Authors: Drude Molbo, Carlos A Machado, Edward Allen Herre, Laurent KellerAbstract:We used recently developed microsatellites to directly estimate inbreeding levels in two pairs of coexisting cryptic Fig Wasp species ('Pegoscapus hoffmeyeri sp. A and sp. B', 'P. gemellus sp. A and sp. B'). Previous tests of Hamilton's local mate competition (LMC) theory in Fig Wasps have used the number of dead foundresses in a Fig fruit to indirectly estimate the relative contribution of each to the common brood and thereby the level of local mate competition. Further, the population level of inbreeding has been indirectly estimated using the distribution of foundress numbers across broods. Our direct genetic estimates confirmed previous assumptions that the species characterized by lower foundress numbers showed higher relative levels of inbreeding. However, there were quantitative differences between the observed level of inbreeding and the expectation based on the distribution of foundress numbers in both pollinator species associated with Ficus obtusifolia. Here, genotype compositions of broods revealed that only 23% of fruits with multiple foundresses actually contained brood from more than one foundress, thus explaining at least part of the underestimate of actual sibmating. Within the four Wasp species there was no evidence for genetic differentiation among the Wasp populations sampled from different trees across 20 km and from different points in time. Further, no genotypic disequilibrium was detected within any of the species. Although F1 hybrids were observed between the two species pollinating F. obtusifolia, there was no evidence of genetic introgression. Finally, we found that 11% of the sons of allospecifically mated mothers were diploid hybrids suggesting a break down of the sex determination system in hybrids.
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cryptic species of Fig pollinating Wasps implications for the evolution of the Fig Wasp mutualism sex allocation and precision of adaptation
Proceedings of the National Academy of Sciences of the United States of America, 2003Co-Authors: Drude Molbo, Carlos A Machado, Laurent Keller, Jan G Sevenster, Edward Allen HerreAbstract:Fig-pollinating Wasps have provided model systems for developing and testing theories of the evolution of mutualism, sex allocation, and precision of adaptation. With few exceptions, previous studies have assumed one species of pollinator Wasp per host Fig species. Here we report genetic data demonstrating the coexistence of previously undetected cryptic Fig Wasp species in at least half of the host Fig species surveyed. The substantial mitochondrial sequence differences (4.2–6.1%) imply old divergences (≈1.5–5.1 million years ago) among these species. Furthermore, some cryptic species pairs seem to be sister taxa, whereas others clearly are not, indicating both long-term coexistence on shared hosts and the colonization of novel Fig species. These findings undermine the prevalent notion of strict one-to-one specificity between cospeciating Figs and their pollinators, thereby challenging existing theory concerning the evolution and stability of mutualisms. Moreover, the incorporation of the genetic information significantly improves the fit of the observed sex ratios to predictions of local mate-competition theory, further strengthening support for sex allocation theory and the precision of adaptation.