Neuroterus paradecrescens, a new species of oak gall wasp from Mexico (Hymenoptera: Cynipidae: Cynipini)

Quantifying the frequency of shifts to new host plants within diverse clades of specialist herbivorous insects is critically important to understand whether and how host shifts contribute to the origin of species. Oak gall wasps (Hymenoptera: Cynipidae: Cynipini) comprise a tribe of ∼1000 species of phytophagous insects that induce gall formation on various organs of trees in the family Fagacae—primarily the oaks (genus Quercus; ∼435 sp.). The association of oak gall wasps with oaks is ancient (∼50 my), and most oak species are galled by one or more gall wasp species. Despite the diversity of both gall wasp species and their plant associations, previous phylogenetic work has not identified the strong signal of host plant shifting among oak gall wasps that has been found in other phytophagous insect systems. However, most emphasis has been on the Western Palearctic and not the Nearctic where both oaks and oak gall wasps are considerably more species rich. We collected 86 species of Nearctic oak gall wasps from most of the major clades of Nearctic oaks and sequenced >1000 Ultraconserved Elements (UCEs) and flanking sequences to infer wasp phylogenies. We assessed the relationships of Nearctic gall wasps to one another and, by leveraging previously published UCE data, to the Palearctic fauna. We then used phylogenies to infer historical patterns of shifts among host tree species and tree organs. Our results indicate that oak gall wasps have moved between the Palearctic and Nearctic at least four times, that some Palearctic wasp clades have their proximate origin in the Nearctic, and that gall wasps have shifted within and between oak tree sections, subsections, and organs considerably more often than previous data have suggested. Given that host shifts have been demonstrated to drive reproductive isolation between host‐associated populations in other phytophagous insects, our analyses of Nearctic gall wasps suggest that host shifts are key drivers of speciation in this clade, especially in hotspots of oak diversity. Although formal assessment of this hypothesis requires further study, two putatively oligophagous gall wasp species in our dataset show signals of host‐associated genetic differentiation unconfounded by geographic distance, suggestive of barriers to gene flow associated with the use of alternative host plants.

Cynipids (Hymenoptera: Cynipidae) induce a wide variety of complex galls on plants of different botanical families, particularly on Quercus species. Cynipid galls are well known to host large communities of insects, providing fundamental ecological niches for different animal taxa, which are organized in structured and relatively isolated communities at the microhabitat level. Gall communities of Quercus woodlands could be a conservation concern considering some risks, which affect several species of the Parasitica group of Hymenoptera, within which gall wasps and their parasitoids and inquilines are included. These risks concerning Parasitica species are mainly due to three causes: their high trophic level, high host specialization and the lack of knowledge of their biology. In this paper, a preliminary approach to this issue is presented for the Iberian–Balearic range. We model and study the ecological niche of three cynipid gall species that induce galls on Quercus species (Andricus quercustozae, Biorhiza pallida and Plagiotrochus quercusilicis). The cynipid gall species were selected for their different sets of host species and life cycle. The Ecological Niche Factor Analysis and two niche models built for each species (MAXENT and Mahalanobis Distances) support the interpretation that the bioclimatic variables considered have effects on cynipids through their respective sets of host plants. In addition, the results regarding A. quercustozae are consistent with the hypothetical existence of cryptic sexual generation (exposed in other works) parasitizing cork oak (Quercus suber), which could have another key role in its conservation.

The Asian chestnut gall wasp (ACGW), Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), is a global pest of chestnut trees. This pest was first recorded in Slovenia in 2005. Despite strict phytosanitary measures it was present throughout the country in native chestnut stands by 2013. We provide here the first overview of the parasitoids of ACGW in Slovenia recorded over a 4-year period and the direct interactions between parasitoid communities attacking hosts on chestnut and oaks at the same sites. A total of 27 species of native parasitoids that normally parasitize oak cynipids emerged from ACGW galls. The most abundant species were Torymus flavipes and Eupelmus urozonus. Seven species appear to be geographically well distributed in Slovenia. Twelve species of oak gall wasp were parasitized by 19 species of parasitoids. All native parasitoids have broad host ranges, so a large parasitoid diversity within this community can be expected. This is a novel study comparing the parasitoid communities associated with chestnut and oak galls.

A new species of oak gall wasp, Andricus coombesi Pujade-Villar & Prez-Torres n. sp. from Mexico, known only from its asexual generation that induces galls on acorns of Quercus grahamii Benth., (section Lobatae) is described. Its presence causes the complete disappearance of the acorn. Diagnosis, distribution and biological data of the new species are given. Andricus coombesi Pujade-Villar & Prez-Torres n. sp. represents the first gall wasp species mentioned from this host.

Two new species of oak gall wasps, Cynips izzetbaysali sp. nov. and Callirhytis afion sp. nov. (Hymenoptera: Cynipidae: Cynipini) are described from Turkey. The new Cynips species is known only from asexual females and induces detachable leaf galls on Quercus infectoria. The sexual generation of the new Callirhytis species is known to induce acorn galls on Quercus cerris. Data on the diagnosis, distribution, and biology of the two new species are given.

Populations of the recently described black oak gall wasp, Zapatella davisae Buffington (Hymenoptera: Cynipidae), have been identified as the cause of extensive tree damage and mortality to black oaks, Quercus velutina Lamarck (Fagales: Fagaceae), in the northeastern United States. Relatively little is known, however, about the distribution, phylogenetic placement, and lifecycle of this important tree pest. Therefore, we conducted next-generation sequencing using the Ion Torrent™ PGM (ThermoFisher Scientific, Inc.) platform to develop genomic resources for the study of Z. davisae and for other closely related species of oak gall wasps. Individual sequence reads were aligned, assembled into unique contigs, and the contigs were then utilized for the in silico isolation and development of microsatellite markers. In total, we screened 36 candidate microsatellite loci, of which 23 amplified consistently (five polymorphic and 18 monomorphic). We then examined whether the polymorphic loci could be used to infer whether populations of Z. davisae from Cape Cod and Nantucket are sexual or asexual by calculating several metrics of genetic diversity that might indicate the mode of reproduction. These included testing for statistical deviations from Hardy-Weinberg equilibrium (HWE) and for linkage disequilibrium (LD), observations for the presence of the Meselson effect, and by calculating the probability that clonal individuals are more prevalent than would be expected in a randomly mating population. While we found significant deviations from HWE and more clonal individuals than expected, our estimates of the Meselson effect were inconclusive due to limited sampling, and we found no evidence of LD. Therefore, the sexual/asexual status of Z. davisae populations remains uncertain.

Wolbachia infection in six species of gall wasps and their parasitoids

A new species of oak gall wasp, Andricus protector Pujade-Villar and Cuesta-Porta sp. nova, known only from its asexual generation that induces deciduous galls on buds of Quercus crassifolia Humb. and Bonpl. (Lobatae section), is described from Mexico. Diagnosis, distribution and biological data of the new species are given. The validity of Andricus species from Mexico is commented. Four species are proposed here to have dubious affiliation: Andricus burnetti (Dailey and Sprenger, 1983), A. marmoreus Kinsey, 1920, A. setifer (Karsch, 1880) and A. strues (Kinsey, 1938).

Two new species of oak gall wasp, Andricus mammadovi Azmaz Katlm sp. n. sexual generation and Cynips fatihi Azmaz Katlm sp. n. asexual generation (Cynipidae: Cynipini) are described from the eastern Black Sea region in Turkey. These species induce galls on Quercus pontica K.Koch representing the first record of cynipids associated with the natural Q. pontica population in Turkey. SEM images, photos of the host galls, and data on the diagnosis, distribution, and biology of both new species are provided.

A new species of oak gall wasp, Andricus breviramuli Pujade-Villar n. sp., is described from Mexico. The species is known only from asexual females. Data on the diagnosis, distribution, and biology of the new species are given. The wasp induces galls on twigs and young shoots of Quercus laeta Liebm. This gall wasp seems to be a serious pest of Q. laeta in Santa Fe (Delegación Cuajimalpa, DF), México City.

Patterns of the distribution of species diversity are the result of ecological, physical and historical factors. Beta diversity is an important property of ecosystems because it provides information about the partitioning of habitats by species. The objectives of this study were to determine the level of oak gall wasps diversity present in five different locations and to study the similarity among these locations. The highest amount of Simpson (0.95) and Shannon (2.6) entropy index were recorded in Ghabre-hossein and Dare-ghabr. The Jaccard and Sorensen coefficients revealed extremely close results with multiple site similarity. The multiple-similarity measures indicated that similarity in gall composition and community between collecting sites was generally between 0.25 and 0.97. Our results suggest that more oak gall wasps species had an aggregated distribution, and gall wasps diversity shows a strong beta diversity component. Presence of the rare gall wasps species affected on multiple site similarity value. Difference in the local distribution of oak species, especially oak subspecies, and the climate of the locations shall be considered as one main factor in species diversity and the distribution of gall wasp species in different locations. Key words: Diversity, gall, wasps, similarity, community, distribution.

Abstract. Three related species of oak gall wasps,Andricus corruptrix(Schlechtendal),A. kollari(Hartig) andA. lignicola(Hartig) have entered Britain since the introduction of Turkey oak,Quercus cerrisL. in 1735. Their lifecycles involve alternating generations between an agamic generation on the native oak species (Q. petraea,Q. robur andtheir hybridQ. x. rosacea), and a smaller, sexual generation on the alienQ. cerris. In examining the distributions of these insects andQ. cerris, we hypothesized that: (1) the invasion will spread more rapidly in places where both host trees are equally abundant than through regions where one of the tree species is substantially less common than the other; (2) interspecific competition between these bud‐galling species will lead to a negative correlation between their abundances at a particular site; (3) differential recruitment of natural enemies from the native hymenopteran fauna will slow the rate of spread in a species‐specific manner.A. kollariarrived nearly 200 years ago and is now found throughout the British Isles, wherever Turkey oak is grown.A. lignicolaandA. corruptrixhave been here for 30 years, after establishing in S.E. England.A. lignicolais in its final rapid stages of range expansion across England, southern Scotland and N.E. Scotland.A. corruptrixis just beginning to spread through Central and S.W. England. It has occupied proportionally fewer sites behind its invasion front than have the other two species, but is no less abundant at these sites. Nevertheless, distance leaps of up to 50 km were identified inA. lignicolain N.E. Scotland, and the possibility of long‐distance transport of infected trees through the horticulture and forestry trades remains. The co‐occurrence of mature individuals of both hostQuercusspecies does appear to have increased their rates of colonization inA. lignicolaandA. corruptrix. There is no evidence, however, to suggest that interspecific competition between the three alien gall formers is an important factor in determining their distributions and abundance within their invaded ranges. All three species have recruited parasitoids and inquilines rapidly from the native fauna; attack rates were highly variable, but showed no evidence of density dependence across sites.

Three new species of oak gall wasps of the genus Amphibolips Reinhard, 1865 (Hymenoptera: Cynipidae: Cynipini) are described from Mexico: Amphibolips magnigalla Nieves-Aldrey & Castillejos-Lemus, Amphibolips kinseyi Nieves-Aldrey & Castillejos-Lemus and Amphibolips nigrialatus Nieves-Aldrey & Castillejos-Lemus. The specimens of the first two species were representative of sexual generations and come from the State of Oaxaca, while only a female, collected in the State of Veracruz, is described for A. nigrialatus. The new species induces galls on Quercus zempoaltepecana and Q. sapotifolia (Fagaceae, section Lobatae, red oaks). Descriptions of the diagnostic morphological characteristics of the three species and a key for their identification are provided. The taxonomic relationships of the new species with other species of Amphibolips are discussed; the three new species are closely allied amongst themselves and are related to A. dampfi Kinsey, 1937. With the three newly-described species, the number of Amphibolips in Mexico is increased to 23.

Two new species of herb gall wasps (Hym., Cynipidae) developing on plants in the genera Sonchus L. and Crepis L. (Asteraceae) are described from Southeastern Romania (Dobrogea Province): Aulacidea andriescui sp. n. gall inducer on Sonchus palustris L. and Phanacis dobrogicus sp. n. gall maker on Crepis foetida subsp. rhoeadifolia (M. Bieb.) Čelak. In addition to the diagnosis, identification, morphological description, life-cycle, geographical distribution, photos of gall and host plant, and SEM images, data on the associated fauna obtained from the galls of the two new species are also presented.

A new species of the genus Andricus Hartig, 1840 (Cynipidae: Cynipini) is described from Burdur province in Turkey: Andricus arslani Azmaz Katlm sp. n. sexual generation. The new species induce galls on Quercus cerris L. belonging to section Cerris. SEM images, photos of the host galls, and data on the diagnosis, distribution, and biology of the new species are provided.