Darwell et al. BMC Ecol (2018) 18:13
https://doi.org/10.1186/s12898-018-0167-y

BMC Ecology

RESEARCH ARTICLE

Open Access

Conserved community structureand simultaneous divergence events in the
fig wasps associated with Ficus benjamina
in Australia and China
Clive T. Darwell1,2 , Simon T. Segar1,3 and James M. Cook1,4*

Abstract
Background: Localised patterns of species diversity can be influenced by many factors, including regional species pools, biogeographic features and interspecific interactions. Despite recognition of these issues, we still know
surprisingly little about how invertebrate biodiversity is structured across geographic scales. In particular, there havebeen few studies of how insect communities vary geographically while using the same plant host. We compared thecomposition (species, genera) and functional structure (guilds) of the chalcid wasp communities associated with thewidespread fig tree, Ficus benjamina, towards the northern (Hainan province, China) and southern (Queensland, Australia) edges of its natural range. Sequence data were generated for nuclear and mtDNA markers and used to delimit
species, and Bayesian divergence analyses were used to test patterns of community cohesion through evolutionary
time.
Results: Both communities host at least 14 fig wasp species, but no species are shared across continents. Community composition is similar at the genus level, with six genera shared although some differ in species diversity
between China and Australia; a further three genera occur in only China or Australia. Community functional structure
remains very similar in terms of numbers of species in each ecological guild despite community composition differing a little (genera) or a lot (species), depending on taxonomic level. Bayesian clustering analyses favour a single
community divergence event across continents over multiple events for different ecological guilds. Molecular dating
estimates of lineage splits between nearest inter-continental species pairs are broadly consistent with a scenario ofsynchronous community divergence from a shared “ancestral community”.
Conclusions: Fig wasp community structure and genus-level composition are largely conserved in a wide geographic comparison between China and Australia. Moreover, dating analyses suggest that the functional community structure has remained stable for long periods during historic range expansions. This suggests that ecologicalinteractions between species may play a persistent role in shaping these communities, in contrast to findings in somecomparable temperate systems.
Keywords: Barcoding, Chalcidoidea, Community composition, Biodiversity, Ficus, Galler, Parasitoid, Wasp
Background
Recent decades have heralded the realisation thatto understand how species diversity is generated,*Correspondence: james.cook@westernsydney.edu.au
4
Hawkesbury Institute for the Environment, Western Sydney University,
Locked Bag 1797, Penrith, NSW 2751, Australia
Full list of author information is available at the end of the article

maintained and distributed we must investigate theevolutionary histories of organisms in conjunction with
regional patterns and processes [1–3]. Moreover, as diversity is composed of species whose evolutionary viability
depends partly on species interactions, it is important toinvestigate patterns of biodiversity in a community context [4, 5]. In geographically wide-ranging communities,© The Author(s) 2018. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License(http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium,provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license,
and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/
publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Darwell et al. BMC Ecol (2018) 18:13

there may be species turnover along environmental andgeographical gradients, leading to high β-diversity (thedegree of turnover in species composition across sites),even if measures of local α-diversity remains the same[6]. If ecological processes are the primary force governing species’ occurrences, one would predict convergencein community structure at a regional scale given similar
local abiotic and biotic conditions. Alternatively, spatial
turnover of species may facilitate divergence in community composition and structure between environmentallyand geographically distinct regions [7, 8], if species arelost or gained.
While considerations of community structure often
assume that niche space is filled, geographic variation
in local species diversity may indicate vacant niches insome populations [9–11]. Communities utilising thesame resources in geographically disparate regions may
be taxonomically (and even functionally) dissimilar[11], suggesting that community composition and structure may depend more strongly on stochastic recruitment processes, the regional species pool, phylogenetic
constraints, or intrinsic differences in the key resources
upon which communities are founded, rather than being
driven by interspecific interactions.
One approach to better identify underlying processes,
both within and between trophic levels, and determine
drivers of community assembly at wide geographic scales,
is to compare the divergence histories of interacting species [12]. Communities in which species have dispersed
at different times from source populations have likely
experienced intermittent interspecific interactions. Sucha history reduces potential for coevolutionary dynamics
to shape community assembly and increases the opportunities for colonisation of certain niches by other species. This may facilitate ecological dominance for earlycolonisers that can monopolise resources and impede
species at higher trophic levels that cannot invade new
populations until their target resources arrive.
Alternatively, continuous associations among species are consistent with strong coevolutionary interactions leading to more specialised life-history strategies,
a potential concomitant increase in diversity [13], anda reduced capacity for species-pool recruitment due tostabilised ecological interactions. In one well-studied
system—communities of Palearctic oak gall wasps andtheir parasitoids—population histories are dominatedby Pleistocene glacial maxima that restricted species tosouthern refugia [12]. Subsequent diversification among
these species occurred in western Asia and was followed
by westward pulses of range expansion, with gall-making
herbivores preceding their parasitoid predators and thus
“enjoying” periods of enemy-free space. It is unknown
whether such patterns are common in tropical systems,

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which are unlikely to have been so strongly affected byglacial refugia.
Herbivorous insects and their parasitoid enemies
comprise a large proportion of terrestrial biodiversity.
As such they are of profound ecological importanceand engage in a vast repertoire of trophic interactions[14–17]. Nevertheless, relatively little is known about thediversity, distribution and biology of many such insectgroups, especially in tropical regions, and there havebeen few studies comparing herbivore and parasitoid
assemblages on the same host plant between geographical regions [18]. Many insect herbivores, and the majorityof all parasitoids, belong to the insect order Hymenoptera [19] and a number of studies have focused on themultitrophic insect communities associated with the figpollinator mutualism [e.g. 20–26].
Ficus is a ubiquitous tropical and sub-tropical resource,
comprising around 750 species that provide year-round
fruit resources for diverse animals. Fig-wasp community structure is complex, typically involving coexistenceof five functional groups [21] or ecological guilds. Small
herbivorous wasp species may be pollinators (guild 1)
or non-pollinators (guild 2) with both groups galling fig
flowers. These small galler guilds are exploited by (guild3) kleptoparasites/inquilines (that usurp these galls) orparasitoids. Large wasp species, in turn, may be gallers(guild 4) of fig wall tissue or flowers, or parasitoids (guild5) of large gallers. While several fig wasp communities
have been studied, there have been few comparisons ofentire fig wasp communities in different geographic areas[26–28] and none using molecular tools to investigate
diversity and divergence histories (but see [29] for work
focussed on particular fig wasp guilds).
Here, we focus on the wasp community of the tropical fig species, Ficus benjamina (Conosycea, Moraceae),
which is widespread and common from India to China at
the northern limits of its range, and through Southeast
Asia to northern regions of Australia at its southern limits. It thus occurs in both the Oriental and Australasianregions. Ficus section Conosycea is thought to have originated in India and radiated across Asia around 35 Mya[30]. After this, it may have ‘rafted’ across the Wallace
line on a fragment of Borneo, as is hypothesised for many
Asian plants. We compare the morphological and molecular community description of F. benjamina fig wasps inHainan province, China [22] with our own data for theAustralian F. benjamina fig wasp community in Queensland (Australia) to investigate how the species composition and trophic structure of the community varies acrossits wide geographic range.
We employ molecular species delimitation methods
to ascertain whether species from China are also present
in Australia and to ascribe genera into taxonomicallyDarwell et al. BMC Ecol (2018) 18:13

associated functional groupings that we refer to as ecological guilds. Given the wide geographic separation of thetwo communities, we predicted few shared species. However, as the two communities occupy similar (northern andsouthern) latitudes, we predicted that they should display
convergent community composition at higher taxonomic
levels (genera, subfamilies). Further, we use moleculardating methods to establish the degree of community
cohesion across evolutionary time. As previous work on
temperate oak gall wasp communities has shown evidenceof temporal tracking of parasitoid species following theirgalling hosts during range expansion [12], we expected tosee similar patterns among these fig wasp communities.

Methods
Study system and sampling

Xiao et al. [22] identified seven genera of chalcid fig
wasps from their sampled community in Hainan province, China (19.2175°N, 109.8127°E). Ficus benjamina
is pollinated by Eupristina koningsbergeri, which, alongwith the externally ovipositing Walkerella spp. (Pteromalidae, Otitisellinae), comprise the small galling species in this community. Attacking these are the smallparasitoid genera Philotrypesis and Sycoscapter (Pteromalidae, Sycoryctinae). Among the large wasps, Sycobia
and Acophila (both Epichrysomallinae) are large gallers,
whilst their parasitoid enemies are from the genus Sycophila (Eurytomidae). Additionally, Xiao et al. [22] identified two individuals of Ormyrus (Ormyridae), a rarelarge species whose life habit is unknown. Figure 1 shows
the simplified community structure of F. benjamina fig
wasps according to our current understanding of theirecological guilds distinguished according to trophic role
and adult wasp body size [21].
The Australian wasp community from F. benjamina figs
was sampled periodically in northern Queensland, from
Lake Eacham (17.2848°S, 145.6259°E; 1998/99), Yungaburra (17.2705°S, 145.5829°E; 2007), Cairns (16.9127°S,
145.7709°E; 1995, 1998/99, 2003, 2004, 2007 and 2008)
and Townsville (19.2575°S, 146.8178°E; 2008). Near-ripe
figs were collected from trees and placed into plastic
hatching pots with meshed lids that allow air-flow, butprevent overheating and wasp escape. After 48 h each
fig and any emerged wasps were placed into 70% ethanol. Alternatively, figs were placed directly into alcoholand wasps were dissected out of their galls at a later date.
Wasps were easily identified to genus using the key of
Bouček [31] and cross-checking with the images of Xiao
et al. [22]. Species level designations were then madeusing molecular data, since the majority of fig wasp species remain undescribed.
We sequenced the following numbers of individuals from each constituent wasp (sub)family:

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Agaonidae: Eupristina (9); Sycoryctinae: Philotrypesis(50); Sycoscapter (18); Sycorycteridea (6); Epichrysomallinae: Sycobia (9); Eurytomidae: Sycophila (14); Otitesellinae: Walkerella (24). The genetic sampling effort reflects
our perception of the morphological diversity weobserved within each genus. Individuals for sequencing
were chosen to represent observed colour and size variation. For genera where sample numbers are low (i.e. < 10individuals), sample sizes represent the maximum number of individuals available to us, i.e. without sequencing multiple non-independent monomorphic individuals
from the same figs. Although it would have been betterto have identical sampling schemes across communities,
there is no information in Xiao et al. [22] regarding sampling effort. However, as we have sampled a similar number of individuals and genera, it is likely that the sampling
effort employed in both studies is similar.
For molecular species comparisons, we used the corresponding sequence data for wasps from the study of
F. benjamina in Hainan province, China [22], downloaded from Genbank (Accession Numbers: FJ438013–
FJ438369). The Chinese dataset comprises 70 COI and
ITS2 sequences with the following sample sizes by genus:
Eupristina koningsbergeri-6; Sycophila-9; Philotrypesis-17; Sycoscapter-9; Walkerella-20; Acophila-6 (Epichrysomallinae); Sycobia-7; and Ormyrus-2 (Ormyridae).
Molecular methods

A Chelex method [32] was used to extract DNA from
Australian samples and a mitochondrial (cytochrome coxidase subunit I-COI; primers CI-J-1751 and CI-N-2191[33]) and a nuclear (Internal Transcribed Spacer region
2-ITS2 [34]) marker were amplified. This region of COI is
shorter than the standard barcoding region, as alternate
primers have been designed to avoid amplification of
nuclear pseudo-genes [see 22]. Amplification of COI wascarried out using a Techne Touchgene gradient machinewith 5 min at 94 °C, 30 cycles of 30 s at 94 °C, 45 s at
50 °C, 60 s at 72 °C then 10 min at 72 °C. Amplification of
ITS2 was with 5 min at 94 °C, 35 cycles of 30 s at 94 °C,
40 s at 55 °C, 40 s at 72 °C then 10 min at 72 °C. Subsequent purification and sequencing reactions were conducted by Beckman Coulter. Purification was performed
using ethanol precipitation and sequencing by BigDyeTM terminator cycling conditions and a 3730xl DNA
analyser.
Sequence alignment, phylogenetic analysis and speciesdelimitation

New sequences were checked using the chromatogramvisualisation software Finch TV Version 1.4.0 and wereedited and aligned using BioEdit [35]. Final adjustments
were made by eye. Bayesian methods were employed toDarwell et al. BMC Ecol (2018) 18:13

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Philotrypesis sp. A1

Sycophila sp. A1

Philotrypesis sp. A2
Philotrypesis sp. A3

Sycophila sp. A2

Sycorycteridae sp. A1
Sycophila sp. A3

Sycoscapter sp. A1
Sycoscapter sp. A2
Sycoscapter sp. A3

Eupristina sp. A1

Walkerella sp. A1 and sp. A2

Sycobia sp. A1

Fig Tissue

Philotrypesis sp. C1

Sycophila sp. C1

Philotrypesis sp. C2
Philotrypesis sp. C3

Sycophila sp. C2

Philotrypesis sp. C4
Ormyrus sp. C1

Sycoscapter sp. C1
Sycoscapter sp. C2

Eupristina sp. C1

Walkerella sp. C1 and sp. C2

Sycobia sp. C1 Acophila sp. C1

Fig Tissue
Fig. 1 A graphical summary of the proposed trophic interactions between the wasps associated with F. benjamina. Summaries of network structure
are given for both Australian (AUS), above, and Chinese (CN), below, networks. Genus level representative silhouettes of wasps are given for size
comparison and visualisation purposes only. Alpha-numeric species designations are assigned according to region and genus; e.g., Australian Walkerella species 1 is assigned ‘Walkerella A1’

Darwell et al. BMC Ecol (2018) 18:13

construct phylogenies for each marker using MrBayes[36]. The best model of nucleotide substitution for eachgene was determined using likelihood ratio tests with
MrModeltest in PAUP* [37]. For both markers the general time reversible (GTR + I + R) model of evolution waschosen.
Species richness was calculated using the barcoding
criteria of monophyletic lineages of individuals (here forboth markers) with at least one other conspecific within
a commonly used cut-off threshold of 3% K2P (Kimura2-parameter measure of pairwise genetic distance [38])pairwise difference in the COI marker [39], or the 95%
confidence interval of all intraspecific distances [40]. COI
K2P distances were calculated [in Mesquite; 41] for congeneric sister clades of wasps from different continents.
We then further tested these species hypotheses on COI
sequences using the jMOTU software package [42] thatis designed to cluster sequences according to a range ofcut-off values—an inflection point in jMOTU outputs
purportedly shows the barcoding gap.
Historical divergence

To test if intercontinental divergences were clusteredby ecological guild we used a hierarchical approximate
Bayesian computation (hABC) coalescent approach thatallows for species-specific demographic variation andmutation rate heterogeneity [PyMsBayes; 43] on our
COI data. To test different hypotheses of clustered species divergences we used a subset of eight species pairschosen according to the following criteria: each species (China and Australia) had at least two representative COI sequences, and clear intercontinental splits
between clades (Figs. 2, 3) could be identified in bothgenes for the species pair. Thus, we conducted pairwise
comparisons on: Eupristina (species C1 & A1), Philotrypesis (species C3 & A3), Sycoscapter (species C1 &A1), Walkerella (species C1 & A1), Sycobia (species C1& A1) and Sycophila (species C2 & A2), for our analyses.
To guard against sensitivity of results to prior selection
decisions we selected priors according to three separate
divergence scenarios (two, four and six divergences) following instructions from the PyMsBayes manual (http://
joaks1.github.io/PyMsBayes/; Accessed May 2016). We
set a diffuse concentration shape parameter of 2 and set
theta parameters according to the molecular clock rate of
Lin et al. [1.9%; 44]. All other settings were left as default.
We evaluated several models based on differential
divergences according to combinations of guilds to test
individual hypotheses that certain ecological guilds diversified earlier or later than others. The evaluated models
were: all species diverged simultaneously, galling species
diverged before parasitoids, small species diverged before
large species, all small species diverged simultaneously,

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small gallers diverged before small parasitoids, pollinators and small parasitoids diverged simultaneously, pollinators diverged before small parasitoids, all large species
diverged simultaneously, and large gallers diverged
before large parasitoids. We then used Bayes factors bothto evaluate support for each individual model and thenfor direct comparisons between specific scenarios using
the criteria of Raftery [45] to infer preferential support
between models.
Divergence dating and community structure

Split dates between congeneric species were estimatedfrom COI data using Bayesian dating analyses in BEAST
v.1.7.1 [46]. As mitochondrial DNA (mtDNA) evolves
quickly and relationships among deeper nodes lose signal(e.g. within a multi-family phylogeny), we ran individual
analyses on the following genera: Eupristina, Walkerella,Philotrypesis, Sycobia and Sycophila, as well as on the
Sycoryctini tribe (Sycoscapter and Sycorycteridea). As no
fossil calibration points are available, a molecular clock,estimated for Asian fig wasps (1.9% pairwise divergenceper million years; [44, 47]), was imposed. Bayes factors(BF) were calculated using Raftery’s [45] logarithmic scale­(2loge(BF)) to detect the most suitable models of substitution, molecular clock and speciation (where values of
2–5 on this scale are considered positive evidence, > 5 isstrong evidence, and > 10 is very strong evidence). Two
independent runs of 120 million iterations were run foreach species separately. Genealogies and model parameters were sampled every 6000 iterations and 95% highest
posterior densities (HPD) were employed as credibility
intervals. The first 2000 trees of each run were discarded
as the “burn-in” period.

Results
Sequencing results

For the Australian wasps, we obtained sequences from
117 individuals for ITS2 and 83 for COI. Several individuals could not be amplified successfully for one
marker despite successful amplification of the other.
The COI sequences were standardised to a 394 bp fragment alignment, while ITS2 sequences varied between
328–562 bp according to genus: Sycobia—557–562 bp;
Philotrypesis—341–360 bp; Sycophila—328–456 bp;
Walkerella—346–348 bp; Sycorycteridea—306–314 bp;
Sycoscapter—365–405 bp, with sequence length variation
attributable to indel events.
Species delimitation

Identification of congruent monophyletic lineages
between Bayesian phylogenies constructed from COI and
ITS2 markers suggests that wasp communities in China
and Australia each have 14 species (Table 1; Figs. 2, 3;

Darwell et al. BMC Ecol (2018) 18:13

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Fig. 2 Collapsed consensus Bayesian topology of the mtDNA COI region for 158 chalcid fig-wasps from F. benjamina from China and Australia. All
posterior node probabilities > 0.95 except where noted. Clade and terminal branch colours represent taxonomic groupings of taxa correlating withecological function (see legend). Within individual groupings, darker colours represent Chinese samples. Stars denote notable features discussed in
the results section (i.e. taxa without alpha-numeric species designations)

Additional file 2). Species assignations were congruent
between molecular markers except for two cases (Australian Philotrypesis species 4 and Chinese Walkerella
benjamini—dark purple stars and orange stars respectively in Figs. 2, 3). Additionally, two instances among

Australian samples warrant consideration as possible
additional species: in Philotrypesis, a coherent cladeof three individuals is apparent in the ITS2 phylogeny(pink star: Fig. 3) that did not yield PCR products for
COI; and within Walkerella, a singleton wasp appears asDarwell et al. BMC Ecol (2018) 18:13

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Fig. 3 Collapsed consensus Bayesian topology of the nuclear ITS2 region for 205 chalcid fig-wasps from F. benjamina from China and Australia. All
posterior node probabilities > 0.95 except where noted. Clade and terminal branch colours represent taxonomic groupings of taxa correlating withecological function (see legend). Within individual groupings, darker colours represent Chinese samples. Stars denote notable features discussed in
the results section

a distinct clade for both genes (black star). Most identified species meet the barcoding criteria employed for
COI sequence data. However, a few individuals among
Chinese Sycobia and Chinese Philotrypesis species 3 do

not have a putative conspecific falling within the thresholds limits (Table 2). Nevertheless, for all these individuals, their most closely matched individual resides
within their continental monophyletic clade. For eachDarwell et al. BMC Ecol (2018) 18:13

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Table 1 Fig wasp communities found in Chinese and Australian populations of F. benjamina
Genus

Ecological guild

China

Australia

No. of species

Intrageneric K2P (%)

No. of species

Intrageneric K2P (%)< 0.5

Eupristina

Small galler

1

< 1.2

1

Philotrypesis

Small parasitoid

4

< 19

3a

< 13

Sycoscapter

Small parasitoid

2

< 14

3

<3
<2

Sycorycteridea

Small parasitoid

–

–

1

Walkerella

Small galler

2

< 17

2a

< 14

Sycobia

Large galler

1

< 11

1

<4

Sycophila

Large parasitoid

2

< 16

3

< 18

Acophila

Large galler

1

<2

–

–

Ormyrus

Large parasitoid

1

–

–

–

Total

14a

14

Intrageneric K2P (%) indicates maximum range of pairwise Kimura 2-parameter distances for mtDNA COI across congeneric species within communitiesa

Possible extra species

Table 2 Kimura 2-parameter (K2P) distances between congeneric taxa and their nearest alternate continental neighbours
Sycobia Sycophila

Sycophila

Walkerella

Walkerella

Philotrypesis

Philotrypesis

Chi sp1–Aus sp1 Chi sp2–Aus sp2 Chi sp1–Aus sp1 Chi sp2–Aus sp2 Aus sp3–Chi sp3 Chi sp1–Aus sp1
Intraspecific K2P (%)

0–11

0–2

0–1

0–5.1

0–5

0–5.8

0–2.7

Interspecific K2P (%)

6.5–14.4

12–13

12–13

5.9–12

11–14

4.2–6.1

6–8

community, intrageneric pairwise COI K2P distances
are generally similar between continents (Table 1). However, notable exceptions include Australian Sycoscapter
COI distances (~ 3%), which are much lower than for
their Chinese counterparts (~ 14%), and Chinese Sycobia(~ 11%), that have greater divergences than the Australian species (~ 4%). Nearly all of these species hypotheses
are supported by jMOTU analyses conducted on COI
data (Additional file 1: Figure S1). However, the resultsfor Sycobia (Additional file 1: Figure S1e) are ambiguous
due to the Chinese samples, which display large pairwise
genetic distances and form polytomies in the COI phylogeny. Nevertheless, ITS2 (Additional file 2: Figures S2,
S3) data suggest that they are a cohesive species.
Comparative community composition

Most genera were found in both continents, but Ormyrus
and Acophila were present only in China, and Sycorycteridea only in Australia. The Australian community also
harbours more species among the genera Sycoscapter andSycophila. However, both the Chinese and the Australian communities possess a full complement of both small
and large gallers and parasitoids and therefore display
the full range of fig wasp guilds. None of the 28 (or more)
species found in China and Australia are shared between
the two continents (Figs. 2, 3). However, for both genes

there are seven instances in which intercontinental species pairs are more closely related to each other than they
are to a local congener (e.g., in Walkerella, Philotrypesis
and Sycophila; Table 2 records pairwise genetic distances
for these cross-continental phylogenetic sister species
pairs).
Historical divergence

Analyses of community divergence in PyMsBayes did notsupport temporal clustering of distinct divergence events
according to ecological guilds (Table 3). In all scenarios,a model of a single divergence event was favoured overmodels of multiple divergences with 7/12 tests resulting in substantial support (i.e. ­2loge(BF) > 2; [45]) for
the single divergence event. The two, four and six divergence scenarios all gave a similar estimate of around
5.2 ± 1.2 Ma for the single diversification event.
Divergence dating

For molecular dating in BEAST, Bayes Factors indicatedthat sequence alignments for all taxa should be partitioned into three separate codons with several distinct
models for sequence evolution, molecular clock and tree
prior (Additional file 1: Table S1). Bayesian estimates of
intrageneric divergence times between reciprocal Australian–Chinese clades suggest that these communities

Darwell et al. BMC Ecol (2018) 18:13

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Table 3 PyMsBayes evaluation of temporal clustering of divergence events according to various combinations of ecological guilds of intercontinental species pairs
Divergencemodel

Two divergence events

Four divergence events

Posteriorprobability

Prior probability

Bayes factor Posterior
probability

0.696

0.422

3.142**

Six divergence events

Prior probability

Bayes factor Posterior
probability

0.081

6.978**

Prior probability

Bayes factor

0.011

18.381**

All taxa
All synchronised

0.382

0.164

Small > large

00.00072000.00048

0

0

Gallers > parasitoids

00.00024

0

0.002

→0

→0

0.001

→0

→0

All synchronised

0.719

0.475

2.828

0.411

0.115

5.395

0.185

0.021

10.400*

Gallers > parasitoids

0.011

0.008

1.437

0.013

0.005

2.875

0.004

0.00291.390

Pollina0.733
tors = parasitoids

0.531

2.420

0.424

0.157

3.945

0.205

0.030

8.474

Pollinators > parasitoids

0.043

0.0317

1.372

0.062

0.0312

2.052

0.032

0.011

3.097

All synchronised

0.814

0.582

3.138*

0.554

0.211

4.646*

0.303

0.0576

7.113*

Gallers > parasitoids

0.02

0.051

0.381

0.055

0.071

0.767

0.089

0.0466

2.000

→0

→0

Small wasps

Pollinators and small parasitoids

Large wasps

Data are shown for three separate runs with priors set according to two, four and six divergence events. Bayes factors (BF) in italics represent favoured model. Asterisk
indicates positive evidence (i.e. ­2loge(BF) is between 2–5) for favoured model [45]. Two asterisks indicate very strong evidence (NB where posterior probability = 0,
support calculation effectively becomes ­2loge(∞)). Pairwise comparison were made between all scenarios under each sub-heading (in italics). →0 indicates tending
to zerodiverged ca. 4–16.5 Ma (Figs. 4, 5). The deeper species
splits evident in Walkerella (17.5 and 25 Ma) are not
between obvious reciprocal Australian–Chinese counterpart species pairs and may have occurred external to theF. benjamina microcosm (Figs. 4b, 5). In general, galling
species appear to have diversified before the parasitoids,
supporting the temporal tracking hypothesis. However,
the most ancient split of 16.5 Ma is not in gallers but inthe kleptoparasite genus Philotrypesis, and occurred
before the split for the obligate pollinator Eupristina(9 Ma; but see “Discussion”). Notably, the large 95%
HPD error bars mean that the divergence time estimatesshould be treated with some caution.

Discussion
There is a dearth of knowledge about how a given community of interacting insect species varies across wide
geographic scales. A key question is whether high beta
diversity typically results in geographic differences incommunity functional diversity or degree of ecologicalsaturation. Moreover, to understand the coevolutionary dynamics underpinning widespread communities

we must compare the demographic histories of interacting species to determine whether or not lineages havediverged simultaneously across regions. If so, they arelikely to have experienced persistent stable interspecificinteractions and coevolutionary partners. Here we examined the predominantly host-specific wasp communities
associated with an individual fig species, F. benjamina, toinvestigate these patterns in tropical regions. Our results
show that genus-level taxonomic composition and species richness are largely conserved between China (Oriental region) and Australia (Australasian region), whichsuggests conserved functional diversity. Moreover, incontrast to data from comparable temperate insect communities [12], interacting lineages appear to have generally diversified simultaneously across regions, which
implies greater ecological stability and a reduced role for
localised asymmetries in functional dynamics.
Species composition

Molecular species delimitation methods employing bothmitochondrial and nuclear markers indicate 14 welldefined species in each of the Chinese and Australian F.

Darwell et al. BMC Ecol (2018) 18:13

Page 10 of 16aEupristina_FJ438016
Eupristina_FJ438020
Eupristina_FJ438017
Eupristina_FJ438014
Eupristina_FJ438013
Eupristina_FJ438015
Eupristina_FJ438021
Eupristina_F307
Eupristina_986
Eupristina_F304
Eupristina_jmc0302
Eupristina_F308
Eupristina_9972
Eupristina_F306
Eupristina_991

1.0
10

9

8

7

6

5

4

3

2

1

b

0

Walkerella_e152f
Walkerella_c72r
Walkerella_DA2001bWalkerella_r1c3
Walkerella_STS0719
Walkerella_pbd13e5
Walkerella_STS0703
Walkerella_DA3001
Walkerella_pbb17g9
Walkerella_DA3007
Walkerella_DA3005
Walkerella_DA4
Walkerella_pba20fl2
Walkerella_STS0721
Walkerella_DA17
Walkerella_STS0702
Walkerella2_STS0702
Walkerella_pba12f4
Walkerella_DA3002
Walkerella_DA3
Walkerella_r1b1
Walkerella_STS0705
Walkerella_FJ438022
Walkerella_FJ438043
Walkerella_FJ438025
Walkerella_FJ438027
Walkerella_FJ438031
Walkerella_FJ438023
Walkerella_FJ438026
Walkerella_FJ438030
Walkerella_FJ438044
Walkerella_FJ438029
Walkerella_FJ438024
Walkerella_benjamini_FJ438039
Walkerella_benjamini_FJ438033
Walkerella_benjamini_FJ438037
Walkerella_benjamini_FJ438034
Walkerella_benjamini_FJ438040
Walkerella_benjamini_FJ438035
Walkerella_benjamini_FJ438032
Walkerella_benjamini_FJ438038
Walkerella_benjamini_FJ438036
Walkerella_DA21
3.0
30

25

20

15

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Sycorycteridea4_STS0703

c

Sycorycteridea_STS0704
Sycorycteridea2_STS0702
Sycorycteridea_STS0703
Sycorycteridea3_STS0703b
Sycoscapter_FJ438053
Sycoscapter_FJ438047
Sycoscapter_FJ438046
Sycoscapter_FJ438045
Sycoscapter_FJ438054
Sycoscapter_STS0719
Sycoscapter_FJ438048
Sycoscapter_FJ438051
Sycoscapter_FJ438052
Sycoscapter_FJ438050
Sycoscapter_STS0719s
Sycoscapter2_STS0704
Sycoscapter3_STS0703
Sycoscapter2_STS0703
Sycoscapter_STS0702
Sycoscapter2b_STS0703
2.0
20

17.5

15

12.5

10

7.5

5

2.5

0

Fig. 4 Bayesian estimation of intrageneric divergence times for fig wasp species in F. benjamina (a) Eupristina; b Walkerella; c tribe Sycoryctini. Divergence between inter-continental species occurred ca. 9–10 Mya in Eupristina; ca. 11–25 Mya in Walkerella; ca. 6–11 Mya in Sycoscapter (ca. 19 Mya in
Sycorycteridea); ca. 4–16.5 Mya in Philotrypesis; ca. 15 Mya in Sycobia; 8–14 Mya in Sycophila. Australian lineages in red

Darwell et al. BMC Ecol (2018) 18:13

Page 11 of 16

Philotrypesis_STS0703
Philotrypesis_STS0721
Philotrypesis_DA14
Philotrypesis_DA3007
Philotrypesis_DA13
Philotrypesis_DA12
Philotrypesis_STS0725
Philotrypesis_STS0702
Philotrypesis_brSTS0719
Philotrypesis_STS0719
Philotrypesis_STS0704
Philotrypesis2_bSTS0719
Philotrypesis_STS1025
Philotrypesis_FJ438058
Philotrypesis_FJ438060
Philotrypesis_FJ438071
Philotrypesis_FJ438059
Philotrypesis_FJ438070
Philotrypesis_FJ438072
Philotrypesis_ySTS0702
Philotrypesis_ySTS0703
Philotrypesis_yDA3004
Philotrypesis_ySTS0721
Philotrypesis_yDA11
Philotrypesis_ypb11g3
Philotrypesis_yDA3005
Philotrypesis_yDA3007
Philotrypesis_yDA3002
Philotrypesis_FJ438074
Philotrypesis_FJ438073
Philotrypesis2_br997
Philotrypesis_br997
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Sycobia_FJ438082
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Sycobia_FJ438078
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Sycophila_STS0702
Sycophila_STS0719
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Sycophila_FJ438091
Sycophila_FJ438089
Sycophila_FJ438094
Sycophila_FJ438090
Sycophila_FJ438093
Sycophila_STS0705
Sycophila_FJ438095
Sycophila_FJ438096
Sycophila_FJ438097
Sycophila_STS0704
Sycophila_DA8
Sycophila_DA7
Sycophila_DA5
Sycophila_DA10
Sycophila_STS07032
Sycophila_STS0720
Sycophila_DA9
Sycophila_STS0703
3.0

25

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5

0

Fig. 5 Bayesian estimation of intrageneric divergence times for fig wasp species in a Philotrypesis; b Sycobia; c Sycophila. Divergence between intercontinental species occurred ca. 9–10 Mya in Eupristina; ca. 11–25 Mya in Walkerella; ca. 6–11 Mya in Sycoscapter (ca. 19 Mya in Sycorycteridea); ca.
4–16.5 Mya in Philotrypesis; ca. 15 Mya in Sycobia; 8–14 Mya in Sycophila. Australian lineages in red

Darwell et al. BMC Ecol (2018) 18:13

benjamina communities. Whilst the various delimitation
criteria gave predominantly congruent species hypotheses, it should be recognised that sole reliance on molecular methods invokes some level of subjective assessment.
In our study this is most evident when considering theobserved variance in intra- and interspecific K2P distances (Table 2), which highlight the arbitrary nature of
employing rigid threshold cut-off values in COI barcoding [e.g. 48]. Although most sampled genera are found inboth regions, one or more are absent from either region(i.e. Ormyrus, Acophila and Sycorycteridea). Although we
did not record Ormyrus from F. benjamina in Australia,
it may be present but rare, as in China where Xiao et al.
[22] only reported two individuals. At the species level,
the Australian community possesses greater species richness in both Sycoscapter and Sycophila. In addition tothese findings there may be an extra two wasp species in
the Australian community whose status is ambiguous due
either to their rarity or to the failure of COI gene amplification (Figs. 2, 3). Additionally, there are three individual
wasps that display phylogenetic incongruence between
their COI and ITS2 sequences.
Comparing ecological guilds across regions

In China, Acophila and Ormyrus are additional large galler and large parasitoid genera not recorded in Australia.
However, the inferred rarity of Ormyrus in China suggests that its apparent absence in Australia is unlikely tohave any major ecological impact on community dynamics. In Australia, the addition of the small parasitoid,
Sycorycteridea, is unlikely to alter community dynamics
greatly, as it is closely allied to Sycoscapter, both taxonomically (both within tribe Sycoryctini [49]) and at afunctional level (small parasitoids [50]). Furthermore,
the Australian community has one or two extra speciesof small galler and one to three extra species of parasitoids (depending on the resolution of the exact numberof species). Despite these differences, each community
has all five fig wasp guilds (pollinators, small and large
gallers, small and large parasitoids), as inferred fromtheir taxonomic affiliations. While it would be of value toinvestigate patterns of relative wasp species abundances
between these two communities, such analyses arebeyond the scope of this work.
If F. benjamina presents the same niches across regions
then community structure in China and Australia ispredicted to be the same. However, a number of factors
may prevent intercontinental ‘mirror-image’ communities. First, environmental conditions may differ between
regions. However, there is no evidence from published
F. benjamina fruit size data across regions to suggest
any ecological differences that would present alternative
niche opportunities typically associated with fig wasps

Page 12 of 16[51–53]. Second, variation in regional species pools
may have resulted in differential recruitment into communities after geographic separation [54]. For example,
although Ormyrus is documented from Australian section Malvanthera Ficus species [55], phylogenetic constraints may prevent it colonising F. benjamina, which
belongs to Ficus section Conosycea.
The extensive contiguous northern Asian landmass
should theoretically host a greater wasp species poolcompared to the northern tip of Australia due to its
greater area (although it is thought that Australia wasconnected to New Guinea in the last 19–30 Ka [56]).
In addition, Conosycea figs probably originated in Asia[57] and have greater extant diversity there than in Australia. Thus, the functional and compositional similarity between the communities suggest that any regional
species pool differences have had little impact. Finally,
differential extinction patterns may have occurred, causing some of the identified disparities in community
composition.
Historical divergence

Simultaneous divergence events were consistently supported over scenarios of multiple divergences according
to guild (Table 3) and we suggest that most membersof the extant Australian and Chinese communities are
inherited from the same “ancestral community” that
already had the major fig wasp guilds established. Differentiation between the extant communities has arisen
primarily by allopatric divergence of these “inherited species”, alongside host range expansion by F. benjamina.
Together, several lines of evidence support this scenario:(i) community-wide synchronised species divergences atappropriate timescales; (ii) conserved community composition involving persistent lineages; (iii) the posited
low permeability to colonisation of fig microcosms; (iv)high levels of fig wasp host fidelity [58]. As such, thesepatterns suggest only a limited role for stochastic or phylogenetically constrained recruitment from regional species pools.
Such synchronised species divergences contrast withfindings from Palearctic oak gall wasp communities,
which are similarly structured around groups of specialised (albeit on Quercus (oak) sections) herbivorous
insects and their parasitoid enemies [12]. Several nonexclusive factors could contribute to these differences:(i) the more stable climatic history of the (sub)tropicalbiome occupied by these figs when compared to temperate systems where demography has been shaped strongly
by retreats into glacial refugia; (ii) lower host-plant specificity (generally host plant sections not species) for oak
gall wasps than fig wasps; (iii) the mutualistic foundationsof fig wasp communities that theoretically generate more

Darwell et al. BMC Ecol (2018) 18:13

tightly bound coevolutionary relationships. Thus, alongside past climatic considerations, relaxation of stringent
interspecific relationships may allow a greater degree of
flexibility among oak gall wasps. Furthermore, it is also
possible that the large intercontinental distances between
these Chinese and Australian communities have blurred
these patterns, especially for the COI marker.
Community composition and structure

No F. benjamina fig wasp species are shared between the
Chinese and Australian communities, which are separated by > 5000 km. In contrast some African fig wasp
communities showed low latitudinal turnover of species
across > 4000 km [26, 28]. There are at least two possible, and not mutually exclusive, explanations for thesedifferences: (i) the African study involves a contiguous
landmass within one region, but our study compares two
different biogeographic regions separated by archipelagic fragmentation, which probably represents a muchstronger barrier to gene flow. (ii) The earlier African
study [26] relied on morphological analyses of insects
so may not have identified genetically distinct entities
within morphospecies. Interestingly, a recent study ofparasitoids in a different fig wasp community along thecontiguous east coast of Australia [59] showed little turnover in morphospecies, but high turnover in cryptic species only recognised with molecular data.
Consideration of phylogenetic relationships suggeststhat these wasp communities may be shaped by ecological interactions between closely related species [60]. For
seven species pairs in the three genera where intercontinental multispecies relationships are clearly resolved—
Walkerella, Philotrypesis and Sycophila—each individual
species’ closest relative is an intercontinental congener.
This suggests that community functional structure has
been consistent through space and time as congenericlineages appear to have persisted rather than suffering
lineage dropout and subsequent replacement by localised
recruitment events or within community cladogenesis.
Among African section Galoglychia figs, community
codivergence between several fig wasp lineages and their
host fig species implicates cospeciation from an ancestral community [61]. This probably results from rigid
coadaptive constraints determined by the fig syconia
that select for high host fidelity [58]. For pollinating species these include optimal body size in order to enter thesmall regulatory entrance (ostiole) to the fig fruit and a
coevolved ovipositor that allows exploitation of the fig
flower gall sites. For parasitic species, ovipositor lengthand strength must be adapted to pierce latex-defended
fig walls that vary between species in thickness and othertraits [62]. These constraints further require wasps toPage 13 of 16

evolve chemosensory recognition of species-specific fig
volatiles to ensure they attack the correct host species.
Thus, although we have shown compositional differences
between the Chinese and Australian communities, theabove factors probably ensure that the degree of differentiation is small compared to many more “open” invertebrate communities, e.g., disjunct bracken herbivore
communities [11] or plant parasitic mites [54], that may
recruit more from regional species pools.
BEAST divergence dating analyses between reciprocal congeneric Chinese and Australian inter-continental pairs generally suggest a split of around 4–16.5 Ma
for these communities, with the higher values seen in
Philotrypesis. Some caution is required with Philotrypesis as individual species have been found to utilise both
F. benjamina and F. microcarpa in China [63]. Thus,
host-switching has occurred in these figs and Philotrypesis lineage divergence may have occurred outside of F.
benjamina. Moreover, relationships within Philotrypesis
appear less clear (Figs. 2, 3) than for other taxa, which isconsistent with data from Australasian (section Malvanthera) figs where Philotrypesis is thought to have entered
the system relatively recently and shows little genetic
divergence between otherwise clearly demarcated, morphologically distinct species [20, 58].
Otherwise, the deepest splits in reciprocal species areat ca. 15 Ma (Sycobia). However, the pollinating Eupristina wasps, which are the obligate insect component of
the fig-wasp mutualism and are therefore expected tohave undergone range expansions more or less contemporaneously with their host, appear to have split more
recently, about 9 Ma. This paradox may be explained by
the remarkable long-distance dispersal abilities of figpollinating wasps [64] that may augment species/population cohesion over greater distances than for the otherwasp species [65] (but see also [66]) and thus retard lineage splitting. Alternatively, Sycobia could have undergone
a genuine early divergence. It belongs to a subfamily oflarge galling wasps (Epichrysomallinae) that can often
develop in unpollinated figs and thus be partly independent of the pollinators. Indeed, F. microcarpa, a close relative of F. benjamina, has been planted extensively outside
its natural range and a recent study reports cases wherelarge gallers were the only wasps present at a given site
[27].
These estimated timescales are later than the hypothesised radiation of section Conosycea from around 35 Ma
proposed by Xu et al. [30] and the collision of the Australian tectonic plate with the Ontong Java plateau around
23–26 Ma [67], and likely correspond to the subsequent
Sunda-Sahul crossing of the Wallace line. Although, dating estimates may be seen to support a divergence modelDarwell et al. BMC Ecol (2018) 18:13

of host tracking (Fig. 4), with parasitoid species diverging after their galling hosts, the large 95% HPD error bars
coupled with our PyMsBayes clustering analyses argue
against such a conclusion.
The wide geographic range of F. benjamina and othersection Conosycea figs makes their wasp communities
ideal candidates for studies of beta diversity patterns andtheir underlying processes [e.g. 68]. The closed nature of
fig microcosms means they are far less open to invasion
than many other insect/plant systems. Thus, their communities are more likely to be organised by a mixtureof both evolutionary history and ecological processes,
rather than from stochastic incursions from other systems. Their ranges from Australia, across the islandarchipelagos of Southeast Asia, and into China and India
would facilitate the study of a large number of distinct
communities with shared evolutionary histories, particularly in an island biogeography framework [69].

Conclusions
It is unknown whether the composition and structureof communities utilising the same ecological resource
generally remain stable across geographic regions, nor
whether species richness and functional diversity area result of the ecological saturation of available niches.
While our results do show some differences in taxonomic
composition at the genus level, the overwhelming picture is of near ‘mirror-image’ communities composedof matching functional groups of wasps. Moreover, evidence that these communities have synchronously diversified across Australasia suggests that historic community
range expansions were undertaken by a full complementof functional groups and that species interaction dynamics and community structure likely remained relatively
stable over evolutionary time and across inter-continental geographic scales. Such mirrored patterns are most
readily explained by ecological saturation dictating community composition although further work is required
to test this idea. Additionally, further work examining
variation in the underlying ecological networks of thesesystems across biogeographic regions would be of significant value.
Additional files
Additional file 1: Figure S1. jMOTU outputs for COI datasets. Largest
inflection points indicate barcoding gaps. Species richness estimatesare: a) Eupristina—two species; b) Walkerella—five species; c) Philotrypesis—eight species; d) tribe Sycoryctini—six species; e) Sycobia—two (orpossibly six) species; Sycophila—five species. Table S1. Chosen models ofmolecular evolution in BEAST dating.
Additional file 2: Figure S2. Bayesian consensus phylogeny for COI
data. Phylogenetic tree. Figure S3. Bayesian consensus phylogeny for ITS
data. Phylogenetic tree.

Page 14 of 16

Authors’ contributions
CTD, STS and JMC conceived the ideas and collected the data; CTD analysed
the data; CTD wrote the first draft of the manuscript, and both CTD and
JMC contributed substantially to revisions with additional input from STS. All
authors read and approved the final manuscript.
Author details
1
School of Biological Sciences, University of Reading, Reading RG6 6AS, UK.
2
Okinawa Institute of Science and Technology, 1919‑1 Tancha, Onna‑son,
Okinawa 904‑0495, Japan. 3 Biology Centre of the Czech Academy of Sciences,
Institute of Entomology and Faculty of Science, University of South Bohemia,
Branisovska 31, 370 05 Ceske Budejovice, Czech Republic. 4 Hawkesbury
Institute for the Environment, Western Sydney University, Locked Bag 1797,
Penrith, NSW 2751, Australia.
Acknowledgements
We would like to thank Brent Emerson for helpful comments regarding thismanuscript, Donna Askew for fig dissection and sample collections, Derek
Dunn for sample collections, and Jamie Oaks for valuable assistance when
performing PyMsBayes analyses.
Competing interests
The authors declare that they have no competing interests.
Availability of data and materials
All molecular sequence data are publicly available on Genbank(Accession Numbers: ITS2-MG907045-114, MG912933–MG912941,
MG912944–MG912951, MG913183–MG913202, MG962537–MG962546;
COI-MG912012–MG912094).
Consent for publication
Not applicable.
Ethics approval and consent to participate
Not applicable.
Funding
CTD was funded by a NERC studentship (#NE/G523912/1): this provided all
sequencing and additional lab costs, and maintenance grant overseeing
periods of analyses and write-up of initial drafts. STS received grant number
15-24571S from the Grant Agency of the Czech Republic that provided support while writing the manuscript. The funding bodies were not involved inany of the following: design of the study; collection, analysis, and interpretation of data; writing the manuscript.

Publisher’s NoteSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Received: 21 February 2017 Accepted: 7 March 2018

References
1. Ricklefs RE. A comprehensive framework for global patterns in biodiversity. Ecol Lett. 2004;7(1):1–15.
2. Ricklefs RE. Coomunity diversity—relative roles of local and regional
processes. Science. 1987;235(4785):167–71.
3. Wiens JJ, Donoghue MJ. Historical biogeography, ecology and species
richness. Trends Ecol Evol. 2004;19(12):639–44.
4. Vellend M, Lajoie G, Bourret A, Murria C, Kembel SW, Garant D. Drawing
ecological inferences from coincident patterns of population- andcommunity-level biodiversity. Mol Ecol. 2014;23(12):2890–901.
5. Schoener TW. The newest synthesis: understanding the interplay of
evolutionary and ecological dynamics. Science. 2011;331(6016):426–9.
6. Whittaker RH. Evolution and measurement of species diversity. Taxon.
1972;21:213–51.

Darwell et al. BMC Ecol (2018) 18:13

7.
8.
9.
10.
11.

12.

13.
14.
15.
16.
17.
18.
19.
20.
21.
22.

23.
24.
25.
26.
27.

28.
29.
30.

Sentis A, Hemptinne J-L, Brodeur J. Towards a mechanistic understandingof temperature and enrichment effects on species interaction strength,
omnivory and food-web structure. Ecol Lett. 2014;17(7):785–93.
Rooney N, McCann KS. Integrating food web diversity, structure andstability. Trends Ecol Evol. 2012;27(1):40–6.
Basset Y, Novotny V. Species richness of insect herbivore communities on
Ficus in Papua New Guinea. Biol J Lin Soc. 1999;67(4):477–99.
Cornell HV, Lawton JH. Species interactions, local and regional processes,
and limits to the richness of ecological communities—a theoreticalperspective. J Anim Ecol. 1992;61(1):1–12.
Lawton JH, Lewinsohn TM, Compton SG. Patterns of diversity for theinsect herbivores on bracken. In: Ricklefs RE, Schluter DC, editors. In species diversity in ecological communities. London: University of Chicago
Press; 1993.
Stone GN, Lohse K, Nicholls JA, Fuentes-Utrilla P, Sinclair F, Schoenrogge
K, Csoka G, Melika G, Nieves-Aldrey J-L, Pujade-Villar J, et al. Reconstructing community assembly in time and space reveals enemy escape in a
Western Palearctic insect Community. Curr Biol. 2012;22(6):532–7.
Smith MA, Eveleigh ES, McCann KS, Merilo MT, McCarthy PC, Van Rooyen
KI. Barcoding a quantified food web: crypsis, concepts, ecology andhypotheses. PloS ONE. 2011;6(7):e14424.
May RM. How many species. Philos Transact R Soc Lond Ser B Biol Sci.
1990;330(1257):293–304.
Lasalle J, Gauld ID. Parasitic hymenoptera and the biodiversity crisis. Redia
Giornale Di Zoologia. 1991;74(N3, Terza Serie, Appendice):315–34.
Bruno JF, Cardinale BJ. Cascading effects of predator richness. Front Ecol
Environ. 2008;6(10):539–46.
Lewis OT, Memmott J, Lasalle J, Lyal CHC, Whitefoord C, Godfray HCJ.
Structure of a diverse tropical forest insect-parasitoid community. J Anim
Ecol. 2002;71(5):855–73.
Lewinsohn TM, Novotny V, Basset Y. Insects on plants: diversity of herbivore assemblages revisited. Annu Rev Ecol Evol Syst. 2005;36:597–620.
Munro JB, Heraty JM, Burks RA, Hawks D, Mottern J, Cruaud A, Rasplus J-Y,
Jansta P. A molecular phylogeny of the Chalcidoidea (Hymenoptera). PloS
ONE. 2011;6(11):e27023.
Segar ST, Dunn DW, Darwell CT, Cook JM. How to be a fig wasp, down
under: the diversity and structure of an Australian fig wasp community.
Acta Oecol Int J Ecol. 2014;57:17–27.
Segar ST, Pereira RAS, Compton SG, Cook JM. Convergent structure of multitrophic communities over three continents. Ecol Lett.
2013;16(12):1436–45.
Xiao J-H, Wang N-X, Li Y-W, Murphy RW, Wan D-G, Niu L-M, Hu H-Y, Fu
Y-G, Huang D-W. Molecular approaches to identify cryptic species andpolymorphic species within a complex community of fig wasps. PloS
ONE. 2010;5(11):e15067.
Kerdelhue C, Rossi JP, Rasplus JY. Comparative community ecology studies on old world figs and fig wasps. Ecology. 2000;81(10):2832–49.
West SA, Herre EA, Windsor DM, Green PRS. The ecology and evolutionof the New World non-pollinating fig wasp communities. J Biogeogr.
1996;23(4):447–58.
Compton SG, Rasplus JY, Ware AB. African fig wasp parasitoid communities. In: Hawkins BA, Sheehan W, editors. Parasitoid community ecology.
Oxford: Oxford University Press; 1994. p. 343–68.
Compton SG, Hawkins BA. Determinants of species richness in southern
African fig wasp assemblages. Oecologia. 1992;91(1):68–74.
Wang R, Aylwin R, Barwell L, Chen X-Y, Chen Y, Chou L-S, Cobb J, ColletteD, Craine L, Giblin-Davis RM, et al. The fig wasp followers and colonistsof a widely introduced fig tree, Ficus microcarpa. Insect Conserv Divers.
2015;8(4):322–36.
Hawkins BA, Compton SG. African fig wasp communities—undersaturation and latitudinal gradients in species richness. J Anim Ecol.
1992;61(2):361–72.
McLeish MJ, van Noort S, Tolley KA. African parasitoid fig wasp diversification is a function of Ficus species ranges. Mol Phylogenet Evol.
2010;57(1):122–34.
Xu L, Harrison RD, Yang P, Yang D-R. New insight into the phylogenetic
and biogeographic history of genus Ficus: vicariance played a relatively
minor role compared with ecological opportunity and dispersal. J Syst
Evol. 2011;49(6):546–57.

Page 15 of 16

31. Boucek Z. Australasian Chalcidoidea (Hymenoptera). A biosystematic
revision of genera of fourteen families, with a reclassification of species.
Wallingford: CABI Publishing; 1988.
32. West SA, Cook JM, Werren JH, Godfray HCJ. Wolbachia in two insect hostparasitoid communities. Mol Ecol. 1998;7(11):1457–65.
33. Simon C, Frati F, Beckenbach A, Crespi B, Liu H, Flook P. Evolution, weighting, and phylogenetic utility of mitochondrial gene-sequences anda compilation of conserved polymerase chain-reaction primers. Ann
Entomol Soc Am. 1994;87(6):651–701.
34. White T, Bruns T, Lee S, Taylor J. Amplification and direct sequencing of
fungal ribosomal genes for phylogenies. In: PCR protocols: a guide tomethods and applications. Ney York: Academic Press; 1990.
35. Hall TA. BioEdit: a user friendly biological sequence alignment editor and analysis program for Windows95/98NT. Nucleic Acids Symp.
1999;41:95–8.
36. Ronquist F, Huelsenbeck JP. MrBayes 3: bayesian phylogenetic inference
under mixed models. Bioinformatics. 2003;19(12):1572–4.
37. Swofford DL: PAUP* phylogenetic analysis using parsimony (*and othermethods). 2002.
38. Kimura M. A simple method for estimating evolutionary rates of basesubstitutions through comparative studies of nucleotide-sequences. J
Mol Evol. 1980;16(2):111–20.
39. Hebert PDN, Cywinska A, Ball SL, DeWaard JR. Biological identifications through DNA barcodes. Proc R Soc Lond Ser B Biol Sci.
2003;270(1512):313–21.
40. Meier R, Shiyang K, Vaidya G, Ng PKL. DNA barcoding and taxonomy indiptera: a tale of high intraspecific variability and low identification success. Syst Biol. 2006;55(5):715–28.
41. Maddison WP, Maddison DR. Mesquite: a modular system for evolutionary
analysis, version 3.04. 2015.
42. Jones M, Ghoorah A, Blaxter M. jMOTU and taxonerator: turning DNA
barcode sequences into annotated operational taxonomic units. PloS
ONE. 2011;6(4):e19259.
43. Oaks JR. An improved approximate-Bayesian model-choice method for
estimating shared evolutionary history. BMC Evol Biol. 2014;14:150.
44. Lin R-C, Yeung CKL, Li S-H. Drastic post-LGM expansion and lack of historical genetic structure of a subtropical fig-pollinating wasp (Ceratosolen sp.
1) of Ficus septica in Taiwan. Mol Ecol. 2008;17(23):5008–22.
45. Raftery AE. “Hypothesis Testing and Model Selection.”, edited by WR. London. In: Gilks WR, Richardson S, Spiegelhalter DJ, editors. Markov chain
Monte Carlo in practice. London: Chapman & Hall; 1996.
46. Drummond AJ, Rambaut A. BEAST: Bayesian evolutionary analysis bysampling trees. BMC Evol Biol. 2007;7:214.
47. Chen Y, Compton SG, Liu M, Chen X-Y. Fig trees at the northern limitof their range: the distributions of cryptic pollinators indicate multiple
glacial refugia. Mol Ecol. 2012;21(7):1687–701.
48. Santos AMC, Besnard G, Quicke DLJ. Applying DNA barcoding for the
study of geographical variation in host-parasitoid interactions. Mol Ecol
Resour. 2011;11(1):46–59.
49. Wiebes JT. The structure of the ovipositing organs as a tribal characters in
the indo-Australian sycophagine Torymidae (Hymenoptera, Chalcidoidea). Zoologische Mededeelingen. 1966;41(9):151–69.
50. Tzeng H-Y, Tseng L-J, Ou C-H, Lu K-C, Lu F-Y, Chou L-S. Confirmation of theparasitoid feeding habit in Sycoscapter, and their impact on pollinatorabundance in Ficus formosana. Symbiosis. 2008;45(1–3):129–34.
51. Dominy NJ, Svenning JC, Li WH. Historical contingency in the evolutionof primate color vision. J Hum Evol. 2003;44(1):25–45.
52. Chew W-L. Hamamelidales to casauarinales. Flora of Australia. Australia:
Australian Government Publishing Service; 1989.
53. Li H. Flora of Taiwan vol2 Angiospermae. Taiwan: Epoch Publishing; 1976.
54. Calatayud J, Horreo JL, Madrigal-Gonzalez J, Migeon A, Rodriguez MA,
Magalhaes S, Hortal J. Geography and major host evolutionary transitions shape the resource use of plant parasites. Proc Natl Acad Sci USA.
2016;113(35):9840–5.
55. Segar ST, Cook JM. The dominant exploiters of the fig/pollinator mutualism vary across continents, but their costs fall consistently on the male
reproductive function of figs. Ecol Entomol. 2012;37(5):342–9.
56. Lambeck K, Chappell J. Sea level change through the last glacial cycle.
Science. 2001;292(5517):679–86.

Darwell et al. BMC Ecol (2018) 18:13

57. Chantarasuwan B, Ronsted N, Kjellberg F, Sungkaew S, van Welzen PC.
Palaeotropical intercontinental disjunctions revisited using a dated
phylogenetic hypothesis with nearly complete species level sampling of
Ficus subsect. Urostigma (Moraceae). J Biogeogr. 2016;43(2):384–97.
58. Cook JM, Segar ST. Speciation in fig wasps. Ecol Entomol. 2010;35:54–66.
59. Darwell CT, Cook JM. Cryptic diversity in a fig wasp community-morphologically differentiated species are sympatric but cryptic species exhibit
competitive exclusion. Mol Ecol. 2017;26(3):937–50.
60. Webb CO, Ackerly DD, McPeek MA, Donoghue MJ. Phylogenies and community ecology. Annu Rev Ecol Syst. 2002;33:475–505.
61. Jousselin E, van Noort S, Berry V, Rasplus J-Y, Ronsted N, Erasmus JC,
Greeff JM. One fig to bind them all: host conservatism in a fig wasp
community unraveled by cospeciation analyses among pollinating andnonpollinating fig wasps. Evolution. 2008;62(7):1777–97.
62. Al-Beidh S, Dunn DW, Power SA, Cook JM. Parasites and mutualism function: measuring enemy-free space in a fig-pollinator symbiosis. Oikos.
2012;121(11):1833–9.
63. Zhou M-J, Xiao J-H, Bian S-N, Li Y-W, Niu L-M, Hu H-Y, Wu W-S, Murphy RW,
Huang D-W. Molecular approaches identify known species, reveal cryptic
species and verify host specificity of Chinese Philotrypesis (Hymenoptera:
Pteromalidae). Mol Ecol Resour. 2012;12(4):598–606.

Page 16 of 16

64. Ahmed S, Compton SG, Butlin RK, Gilmartin PM. Wind-borne insects
mediate directional pollen transfer between desert fig trees 160 kilometers apart. Proc Natl Acad Sci USA. 2009;106(48):20342–7.
65. Kobmoo N, Hossaert-McKey M, Rasplus JY, Kjellberg F. Ficus racemosa ispollinated by a single population of a single agaonid wasp species incontinental South-East Asia. Mol Ecol. 2010;19(13):2700–12.
66. Sutton TL, Riegler M, Cook JM. One step ahead: a parasitoid disperses
farther and forms a wider geographic population than its fig wasp host.
Mol Ecol. 2016;25(4):882–94.
67. Knesel KM, Cohen BE, Vasconcelos PM, Thiede DS. Rapid change in driftof the Australian plate records collision with Ontong Java plateau. Nature.
2008;454(7205):U754–75.
68. Whittaker RH. Evolution and measurement of species diversity. Taxon.
1972;21(2–3):213–51.
69. Macarthur R, Wilson EO. The theory of island biogeography. Princeton:
Princeton University Press; 1967.

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