New herb gall wasps from Iran (Hymenoptera: Cynipidae).

Five new gall wasp species, Aulacidea koeiana Melika, Tavakoli Stone, sp. nov., A. lorestanica Melika, Tavakoli Stone, sp. nov., A. piroziae Melika, Stone Pujade-Villar, sp. nov., Phanacis strigosa Melika, Stone Tavakoli, sp. nov., P. tavakolii Melika, Stone Pujade-Villar, sp. nov. are described from Lorestan, Iran. Descriptions, diagnoses, plus information on biology and host associations are given for all new species, and we provide the first description of the male of Isocolus beheni Melika Karimpour, 2008.

The gall wasp fauna of Iran (Hymenoptera: Cynipidae: Cynipinae): species checklist and biogeographical assessment.

We provide a checklist of the gall wasps (Hymenoptera: Cynipidae: Cynipinae) of Iran, and place these records in a biogeographical perspective on three spatial scales, comprising (i) the Western Palaearctic, (ii) Western Asia (Turkey, the southern Caucasus and the Middle East) and (iii) regions within Iran. We present distribution and biological data for 121 species in 24 genera, representing nine of the 12 known cynipid gall wasp tribes. The most species-rich tribe in Iran is the oak gall wasp tribe Cynipini, with 74 species and 11 genera. Cynipid species richness is highest in the central and northern Zagros, with a distinctively different fauna in the forests along the southern shores of the Caspian Sea. Of the species found in Iran, 63 have distributions that extend westwards far into Europe, and can be considered Western Palaearctic species. Twenty four species comprise a distinct eastern component within the Western Palaearctic, with distributions that include Iran and some or all of Turkey, the Middle East and the Caucasus. Twenty one species are apparently endemic to Iran, with distinct Zagros and Caspian components. We highlight biological and phylogeographic processes that may underlie these patterns.

Molecular identification of Andricus species (Hymenoptera: Cynipidae) inducing various oak galls in Central Zagros of Iran.

This study uses an integrated approach to address the taxonomic status of six different and problematic oak galls and their inducing wasps sampled from two sites in the Central Zagros Mountains (Lorestan province) in western Iran. Our aim was to establish whether morphologically similar but different galls are induced by the same or distinct gall-inducers. The gall wasp specimens were identified morphologically to species level, and their genomic DNA was extracted. We used PCR and Sanger sequencing to amplify three fragments comprising cytochrome oxidase subunit I (COI), cytochrome b (cytB), and a multi-gene fragment of ribosomal DNA (rDNA) including partial 5.8S, complete internal transcribed spacer 2 (ITS2), and partial 28S rRNA. We found that a pair of structurally similar but differently coloured galls are induced by the sexual generation of Andricus grossulariae, while another similar pair are induced by the asexual generation of A. sternlichti. In contrast, we found that two similar galls that differ in some structural details and in developmental phenology are induced by two closely related but different gall wasps; one is the sexual generation of A. cecconii, while the second is a new but closely related sexual generation Andricus sp.

Tournament ABC analysis of the western Palaearctic population history of an oak gall wasp, Synergus umbraculus.

Approximate Bayesian computation (ABC) is a powerful and widely used approach in inference of population history. However, the computational effort required to discriminate among alternative historical scenarios often limits the set that is compared to those considered more likely a priori. While often justifiable, this approach will fail to consider unexpected but well-supported population histories. We used a hierarchical tournament approach, in which subsets of scenarios are compared in a first round of ABC analyses and the winners are compared in a second analysis, to reconstruct the population history of an oak gall wasp, Synergus umbraculus (Hymenoptera, Cynipidae) across the Western Palaearctic. We used 4,233 bp of sequence data across seven loci to explore the relationships between four putative Pleistocene refuge populations in Iberia, Italy, the Balkans and Western Asia. We compared support for 148 alternative scenarios in eight pools, each pool comprising all possible rearrangements of four populations over a given topology of relationships, with or without founding of one population by admixture and with or without an unsampled "ghost" population. We found very little support for the directional "out of the east" scenario previously inferred for other gall wasp community members. Instead, the best-supported models identified Iberia as the first-regional population to diverge from the others in the late Pleistocene, followed by divergence between the Balkans and Western Asia, and founding of the Italian population through late Pleistocene admixture from Iberia and the Balkans. We compare these results with what is known for other members of the oak gall community, and consider the strengths and weaknesses of using a tournament approach to explore phylogeographic model space.

Community impacts of anthropogenic disturbance: natural enemies exploit multiple routes in pursuit of invading herbivore hosts.

BACKGROUND: Biological invasions provide a window on the process of community assembly. In particular, tracking natural enemy recruitment to invading hosts can reveal the relative roles of co-evolution (including local adaptation) and ecological sorting. We use molecular data to examine colonisation of northern Europe by the parasitoid Megastigmus stigmatizans following invasions of its herbivorous oak gallwasp hosts from the Balkans. Local host adaptation predicts that invading gallwasp populations will have been tracked primarily by sympatric Balkan populations of M. stigmatizans (Host Pursuit Hypothesis). Alternatively, ecological sorting allows parasitoid recruitment from geographically distinct populations with no recent experience of the invading hosts (Host Shift Hypothesis). Finally, we test for long-term persistence of parasitoids introduced via human trade of their hosts' galls (Introduction Hypothesis). RESULTS: Polymorphism diagnostic of different southern refugial regions was present in both mitochondrial and nuclear microsatellite markers, allowing us to identify the origins of northern European invaded range M. stigmatizans populations. As with their hosts, some invaded range populations showed genetic variation diagnostic of Balkan sources, supporting the Host Pursuit Hypothesis. In contrast, other invading populations had an Iberian origin, unlike their hosts in northern Europe, supporting the Host Shift Hypothesis. Finally, both British and Italian M. stigmatizans populations show signatures compatible with the Introduction Hypothesis from eastern Mediterranean sources. CONCLUSIONS: These data reveal the continental scale of multi-trophic impacts of anthropogenic disturbance and highlight the fact that herbivores and their natural enemies may face very different constraints on range expansion. The ability of natural enemies to exploit ecologically-similar hosts with which they have had no historical association supports a major role for ecological sorting processes in the recent assembly of these communities. The multitude of origins of invading natural enemy populations in this study emphasises the diversity of mechanisms requiring consideration when predicting consequences of other biological invasions or biological control introductions.

Concordant phylogeography and cryptic speciation in two Western Palaearctic oak gall parasitoid species complexes.

Little is known about the evolutionary history of most complex multi-trophic insect communities. Widespread species from different trophic levels might evolve in parallel, showing similar spatial patterns and either congruent temporal patterns (Contemporary Host-tracking) or later divergence in higher trophic levels (Delayed Host-tracking). Alternatively, host shifts by natural enemies among communities centred on different host resources could disrupt any common community phylogeographic pattern. We examined these alternative models using two Megastigmus parasitoid morphospecies associated with oak cynipid galls sampled throughout their Western Palaearctic distributions. Based on existing host cynipid data, a parallel evolution model predicts that eastern regions of the Western Palaearctic should contain ancestral populations with range expansions across Europe about 1.6 million years ago and deeper species-level divergence at both 8-9 and 4-5 million years ago. Sequence data from mitochondrial cytochrome b and multiple nuclear genes showed similar phylogenetic patterns and revealed cryptic genetic species within both morphospecies, indicating greater diversity in these communities than previously thought. Phylogeographic divergence was apparent in most cryptic species between relatively stable, diverse, putatively ancestral populations in Asia Minor and the Middle East, and genetically depauperate, rapidly expanding populations in Europe, paralleling patterns in host gallwasp species. Mitochondrial and nuclear data also suggested that Europe may have been colonized multiple times from eastern source populations since the late Miocene. Temporal patterns of lineage divergence were congruent within and across trophic levels, supporting the Contemporary Host-tracking Hypothesis for community evolution.

Longitudinal range expansion and cryptic eastern species in the western Palaearctic oak gallwasp, Andricus coriarius.

The oak gallwasp Andricus coriarius is distributed across the Western Palaearctic from Morocco to Iran. It belongs to a clade of host-alternating Andricus species that requires host oaks in two sections of Quercus subgenus Quercus to complete its lifecycle, a requirement that has restricted the historic distribution and dispersal of members of this clade. Here we present nuclear and mitochondrial sequence evidence from the entire geographic range of A. coriarius to investigate the genetic legacy of longitudinal range expansion. We show A. coriarius as currently understood to be para- or polyphyletic, with three evolutionarily independent (but partially sympatric) lineages that diverged c. 10 million years ago (mya). The similarities in gall structure that have justified recognition of single species to date thus represent either strong conservation of an ancestral state or striking convergence. All three lineages originated in areas to the east of Europe, underlining the significance of Turkey, Iran and the Levant as 'cradles' of gallwasp evolution. One of the three lineages gave rise to all European populations, and range expansion from a putative Eastern origin to the present distribution is predicted to have occurred around 1.6 mya.