Hymenopteran parasitoids reared from European gall midges (Diptera, Cecidomyiidae).

We report the results of investigations 2010 through 2023 of hymenopteran parasitoids associated with gall midges in Europe. A total of 242 collections of gall midges were made, from each of which one to several parasitoid species emerged, resulting in ca. 200 recorded parasitoid species and 267 host-parasitoid interaction records. The parasitoid families involved were Eulophidae (63 species), Platygastridae (56 species), Torymidae (34 species), Pteromalidae (31 species), Ceraphronidae (5 species), Eupelmidae (4 species), Eurytomidae (2 species) and Encyrtidae (1 species). As many as 159 interactions are reported for the first time, significantly enlarging our knowledge of gall midge - parasitoid interactions on the species level. Even more interesting, 51 host records are for parasitoid species for which no host was previously known. Similarly, 28 species of gall midge are reported as host to named parasitoids for the first time. Additionally, 91 parasitoid records were the first for the country in question. Differences between the rearing methods applied and their suitability for recording species with contrasting life histories, are discussed.

New records of Chalcidoidea (Hymenoptera) from the Maltese Islands with an updated checklist.

Thirty-three species of Chalcidoidea (Hymenoptera) are newly recorded from the Maltese Islands, of which, 19 include host data. An updated checklist for the 181 chalcidoid species recorded from Malta is also included, which belong to 17 families as follows: Agaonidae (3), Aphelinidae (21, 1 as new record), Azotidae (1), Chalcididae (8 species, 5 as new records), Encyrtidae (24, 1 as new record), Eulophidae (51, 16 are new records), Eupelmidae (9, 2 as new records), Eurytomidae (6, 1 as new record), Leucospidae (4), Megastigmidae (1), Mymaridae (2), Ormyridae (1), Perilampidae (1 new record), Pteromalidae (39, 5 as new records), Signiphoridae (2), Tetracampidae (1) and Torymidae (7, 1 as new record).

Rediscovery of Calymmochilus russoi Gibson, 1995 (Hymenoptera, Chalcidoidea, Eupelmidae), and revision of European Calymmochilus Masi, 1919.

The European species of Calymmochilus Masi (Hymenoptera, Eupelmidae) are revised. Calymmochilus atratus Masi stat. rev. is removed from synonymy under C. subnubilus (Walker) and treated as a valid species. A lectotype is designated for Calymmochilus atratus. The single extant type specimen of Eupelmus subnubilus Walker is considered as lectotype. Calymmochilus bini Fusu sp. n. is described from a single female collected in Sardinia. A female of Calymmochilus russoi Gibson is reported from Spain as a parasitoid in galls of Parapodia sinaica (Frauenfeld) (Lepidoptera, Gelechiidae) on Tamarix (Tamaricaceae), a new national and host record. The species is redescribed and illustrated, this being the first record of the species after its original description. An illustrated key to females and, when known, males of the now six recognized European species of Calymmochilus is given and available biological and distributional data are reviewed.

Checklist of British and Irish Hymenoptera - Chalcidoidea and Mymarommatoidea.

Background A revised checklist of the British and Irish Chalcidoidea and Mymarommatoidea substantially updates the previous comprehensive checklist, dating from 1978. Country level data (i.e. occurrence in England, Scotland, Wales, Ireland and the Isle of Man) is reported where known. New information A total of 1754 British and Irish Chalcidoidea species represents a 22% increase on the number of British species known in 1978.

Catalogue of parasitoids and inquilines in cynipid oak galls in the West Palaearctic.

A quantitative catalogue of the parasitoids (almost exclusively Chalcidoidea) and inquiline Cynipidae recorded in the western Palaearctic from galls induced on Quercus by Cynipidae (Cynipini) is presented. Quantitative and national data are included with bibliographic references to almost all records published in 2011 and earlier. The catalogue is followed by two checklists, firstly one of the Chalcidoidea with numbers of each species recorded from each type of host gall (galls of the sexual and asexual generations of the host gall wasps are listed separately), and secondly one of inquiline Cynipidae with host galls. Compared to non-oak gall wasps, the Cynipini support a much larger parasitoid and especially inquiline fauna, and this fauna is very largely restricted at the species level to Cynipini galls. About one hundred chalcidoid species are recorded from galls of Cynipini, distributed over six families: Pteromalidae and Eulophidae (29 species each), Torymi-dae (21 species), Eurytomidae (10 species), Eupelmidae (8 species) and Ormyridae (at least 2 species). Polyphagy is usual in the chalcidoid parasitoids, most species having a broad host gall range, but quantitatively the fauna of each type of oak gall is rather characteristic and is strongly influenced by gall morphology, situation on the tree, season of growth and host tree species. These and other extrinsic factors restrict the full exploitation of the chalcidoids' potential host gall range.

Reconstructing community assembly in time and space reveals enemy escape in a Western Palearctic insect community.

How geographically widespread biological communities assemble remains a major question in ecology. Do parallel population histories allow sustained interactions (such as host-parasite or plant-pollinator) among species, or do discordant histories necessarily interrupt them? Though few empirical data exist, these issues are central to our understanding of multispecies evolutionary dynamics. Here we use hierarchical approximate Bayesian analysis of DNA sequence data for 12 herbivores and 19 parasitoids to reconstruct the assembly of an insect community spanning the Western Palearctic and assess the support for alternative host tracking and ecological sorting hypotheses. We show that assembly occurred primarily by delayed host tracking from a shared eastern origin. Herbivores escaped their enemies for millennia before parasitoid pursuit restored initial associations, with generalist parasitoids no better able to track their hosts than specialists. In contrast, ecological sorting played only a minor role. Substantial turnover in host-parasitoid associations means that coevolution must have been diffuse, probably contributing to the parasitoid generalism seen in this and similar systems. Reintegration of parasitoids after host escape shows these communities to have been unsaturated throughout their history, arguing against major roles for parasitoid niche evolution or competition during community assembly.

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.