Oak Gall Research Articles

Formulation of Herbal Tooth Powder Employing Quercus infectoria as a Potential Agent for Oral Care and Microbial Infections

Herbal remedies for oral care are increasingly popular due to their safety, affordability, and compatibility with the mouth's natural bacterial balance. This study develops and evaluates herbal tooth powder using Quercus infectoria (oak galls), Triphala (Amla, Haritaki, Bibhitaki), Liquorice (Glycyrrhiza glabra), black salt, and calcium carbonate to prevent oral infections. The objective was to create an effective alternative to conventional dental products. The tooth powder was formulated and tested through physicochemical, rheological, microbiological, patch, and sensory evaluations. The pH level of 5 is ideal for oral applications, balancing effective hygiene and gentleness. Physicochemical evaluations show a moisture content of 1.64% (indicating stability and low microbial risk), an ash value of 0.58% (acceptable limits), and a bulk density of 4g/ml (ensuring good flow and consistent dosing). The effective minimum inhibitory concentration of 0.1 mg/ml highlights the active compounds' potency in inhibiting bacterial growth. Key findings showed it had strong antibacterial, antimicrobial, anti-inflammatory, and antioxidant properties. Tannic acid from Quercus infectoria was effective against oral infections, while Triphala and Liquorice added antibacterial benefits and improved flavour. This study underscores the potential of herbal tooth powders as a natural, effective solution for oral hygiene and infection prevention.

Current and Future Insect Threats to Oaks of the Midwest, Great Lakes, and Northeastern United States and Canada

Increasing temperatures, prolonged drought, the increased severity and intensity of storms, and other effects of climate change are being felt globally, and long-lived forest tree species may struggle in their current ranges. Oaks (Quercus spp.) have evolved a range of adaptations to dry and hot conditions and are believed to be a “climate change winner” by increasing their suitable habitat. However, a mixture of life history traits and increasing susceptibility to herbivores and xylovores as well as secondary pathogen infections still put oaks at risk of decline. Oak species found in the Midwestern, Great Lakes, and Northeastern United States and Canada are important keystone species with high ecological and economical importance. They are also vulnerable to existing, new, and emerging threats that have the potential to cause mortality across entire stands quickly. Current examples of insect threats include the Lymantria dispar (spongy moth), Agrilus bilineatus (twolined chestnut borer), and Nitidulidae (sap beetles) as disease vectors. Examples of emerging insects of concern include Cynipidae (oak gall wasps) and Enaphalodes rufulus (red oak borer). This study describes these insects, explains their mechanisms of action and the effects on oaks, and explores mitigation strategies for each.

Reticulodermis lithogalla gen. nov. and sp. nov. of oak gall wasp from Mexico (Hymenoptera, Cynipidae)

A new genus of oak gall wasp, Reticulodermis Pujade-Villar, Cuesta-Porta & Melika gen. nov. and a new species R. lithogalla García-Martiñón & Pujade-Villar sp. nov. are described from Mexico. Reticulodermis is known only from the asexual generation that induces galls on leaves of Quercus crassipes Humb. & Bonpl. (section Lobatae). We provide the diagnosis, distribution and biological data on the new species. An identification key to the genera of oak gall wasps inducing galls on the section Lobatae is given.

Modelling suggests Wolbachia-induced cytoplasmic incompatibility in oak gall wasps with cyclical parthenogenesis.

Oak gall wasps typically exhibit a life cycle with one sexual and one asexual generation each year. These wasps can carry various endosymbionts, one of which is the maternally inherited bacterium Wolbachia that can induce several reproductive manipulations on its host. Cytoplasmic incompatibility (CI) has been described as the most prominent of these manipulations. CI leads to embryonic mortality in the hosts' offspring when infected males mate with either uninfected females or with females that harbour different Wolbachia strains. It has been hypothesized that Wolbachia can induce CI in oak gall wasps. To address this hypothesis, we derived a mathematical model to investigate the spread of a bacterial infection in naive populations and to determine the plausibility of CI occurrence. To validate our model, we used published data from Wolbachia-infected Belonocnema kinseyi populations in two approaches. Our first approach uses measurements of infection frequencies and maternal transmission in the sexual generation. For the second approach, we extended the model to compare predictions to estimates of mtDNA-haplotypes, which, like Wolbachia, are maternally inherited, and can therefore be associated with the infection. Both approaches indicate that CI is present in these populations. Our model can be generalized to investigate the occurrence of CI not only for oak gall wasps but also for other species.

Comparative transcriptome reprogramming in oak galls containing asexual or sexual generations of gall wasps.

Oak gall wasps have evolved strategies to manipulate the developmental pathways of their host to induce gall formation. This provides shelter and nutrients for the developing larva. Galls are entirely host tissue; however, the initiation, development, and physical appearance are controlled by the inducer. The underlying molecular mechanisms of gall formation, by which one or a small number of cells are reprogrammed and commit to a novel developmental path, are poorly understood. In this study, we sought a deeper insight into the molecular underpinnings of this process. Oak gall wasps have two generations each year, one sexual, and one asexual. Galls formed by these two generations exhibit a markedly different appearance. We sequenced transcriptomes of both the asexual and sexual generations of Neuroterus quercusbaccarum and Neuroterus numismalis. We then deployed Nanopore sequencing to generate long-read sequences to test the hypothesis that gall wasps introduce DNA insertions to determine gall development. We detected potential genome rearrangements but did not uncover any non-host DNA insertions. Transcriptome analysis revealed that transcriptomes of the sexual generations of distinct species of wasp are more similar than inter-generational comparisons from the same species of wasp. Our results highlight the intricate interplay between the host leaves and gall development, suggesting that season and requirements of the gall structure play a larger role than species in controlling gall development and structure.

Description of the first species of gall wasp (Hym., Cynipidae: Cynipini) on Quercus grahamii (Fagaceae).

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.

Roburic acid inhibits lung cancer metastasis and triggers autophagy as verified by network pharmacology, molecular docking techniques and experiments.

Roburic acid (ROB) is a newly discovered tetracyclic triterpene acid extracted from oak galls, which has anti-inflammatory effects, but the mechanism of its anticancer effect is not clear. Our study focuses on exploring the potential mechanism of action of ROB in the treatment of lung cancer using a combination of network pharmacological prediction, molecular docking technique and experimental validation. A network pharmacology approach was used to screen the protein targets of ROB and lung cancer, and PPI network analysis and enrichment analysis were performed on the intersecting genes. The tissue and organ distribution of the targets was also evaluated based on the BioGPS database. To ensure the reliability of the network pharmacology prediction results, we proceeded to use molecular docking technique to determine the relationship between drugs and targets. Finally, in vitro experiments with cell lines were performed to further reveal the potential mechanism of ROB for the treatment of lung cancer. A total of 83 potential targets of ROB in lung cancer were collected and further screened by using Cytoscape software, and 7 targets of PTGS2, CYP19A1, PTGS1, AR, CYP17A1, PTGES and SRD5A1 were obtained as hub genes and 7 hub targets had good binding energy with ROB. GO and KEGG analysis showed that ROB treatment of lung cancer mainly involves Arachidonic acid metabolism, Notch signaling pathway, cancer pathway and PPAR signaling pathway. The results of in vitro experiments indicated that ROB may inhibit the proliferation and metastasis of lung cancer cells and activate the PPARγ signaling pathway, as well as induce cellular autophagy. The results of this study comprehensively elucidated the potential targets and molecular mechanisms of ROB for the treatment of lung cancer, providing new ideas for further lung cancer therapy.

Phytochemical Profiling and Biological Activities of Quercus sp. Galls (Oak Galls): A Systematic Review of Studies Published in the Last 5 Years.

Quercus species have been widely used in traditional medicine, and recently, researchers' attention has focused on galls of the genus Quercus as a source of health-promoting phytochemicals. This review presents a summary of the most recent findings on the phytochemistry and bioactivity of oak galls, following the screening of scientific papers published in two relevant databases, PubMed and Embase, between January 2018 and June 2023. The oak galls are rich in active compounds, mostly gallotannins and phenolic acids. Due to these secondary metabolites, the reviewed studies have demonstrated a wide range of biological activities, including antioxidant and anti-inflammatory actions, antimicrobial properties, tissue-protective effects, and antitumor, anti-aging, and hypoglycemic potential. Thus, oak galls are a promising natural matrix, to be considered in obtaining pharmaceutical and cosmetic preparations used in anti-aging strategies and, together with medications, in the management of age-related diseases. In further evaluations, the valuable functional properties of oak galls, reported mostly in preclinical studies, should be confirmed with clinical studies that would also take into account the potential health risks of their use.

Speciation in kleptoparasites of oak gall wasps often correlates with shifts into new tree habitats, tree organs, or gall morphospace.

Host shifts to new plant species can drive speciation for plant-feeding insects, but how commonly do host shifts also drive diversification for the parasites of those same insects? Oak gall wasps induce galls on oak trees and shifts to novel tree hosts and new tree organs have been implicated as drivers of oak gall wasp speciation. Gall wasps are themselves attacked by many insect parasites, which must find their hosts on the correct tree species and organ, but also must navigate the morphologically variable galls with which they interact. Thus, we ask whether host shifts to new trees, organs, or gall morphologies correlate with gall parasite diversification. We delimit species and infer phylogenies for two genera of gall kleptoparasites, Synergus and Ceroptres, reared from a variety of North American oak galls. We find that most species were reared from galls induced by just one gall wasp species, and no parasite species was reared from galls of more than four species. Most kleptoparasite divergence events correlate with shifts to non-ancestral galls. These shifts often involved changes in tree habitat, gall location, and gall morphology. Host shifts are thus implicated in driving diversification for both oak gall wasps and their kleptoparasitic associates.

Host–enemy interactions provide limited biotic resistance for a range‐expanding species via reduced apparent competition

AbstractAimAs species' ranges shift poleward in response to anthropogenic change, they may lose antagonistic interactions if they move into less diverse communities, fail to interact with novel populations or species effectively, or if ancestral interacting populations or species fail to shift synchronously. We leveraged a poleward range expansion in a tractable insect host–enemy community to uncover mechanisms by which altered antagonistic interactions between native and recipient communities contributed to ‘high niche opportunities’ (limited biotic resistance) for a range‐expanding insect.LocationNorth America, Pacific Northwest.MethodsWe created quantitative insect host–enemy interaction networks by sampling oak gall wasps on 400 trees of a dominant oak species in the native and expanded range of a range‐expanding gall wasp species. We compared host–enemy network structure between regions. We measured traits (phenology, morphology) of galls and interacting parasitoids, predicting greater trait divergence in the expanded range. We measured function relating to host control and explored if altered interactions and traits contributed to reduced function, or biotic resistance.ResultsInteraction networks had fewer species in the expanded range and lower complementarity of parasitoid assemblages among host species. While networks were more generalized, interactions with the range‐expanding species were more specialized in the expanded range. Specialist enemies effectively tracked the range‐expanding host, and there was reduced apparent competition with co‐occurring hosts by shared generalist enemies. Phenological divergence of enemy assemblages interacting with the range‐expanding and co‐occurring hosts was greater in the expanded range, potentially contributing to weak apparent competition. Biotic resistance was lower in the expanded range, where fewer parasitoids emerged from galls of the range‐expanding host.Main ConclusionsChanges in interactions with generalist enemies created high niche opportunities, and limited biotic resistance, suggesting weak apparent competition may be a mechanism of enemy release for range‐expanding insects embedded within generalist enemy networks.

The role of Anatolia between Asia and Europe: A case study of oak gall wasp species, Cynips quercus (Hymenoptera, Cynipidae)

In this study, we used DNA sequence data of a western Palearctic oak gall wasp species, Cynips quercus, showing distribution from Europe to Iran to answer the following questions: i) Do the eastern C. quercus populations have higher genetic diversity than the European populations?, ii) Are the eastern populations source for the European populations?, iii) What is the possible date of divergence between the Asian and European populations? For these purposes, we analysed 88 cytochrome b sequences representing Iran, Türkiye, Hungary, and Spain. Our analyses revealed that the highest genetic diversity was in Türkiye followed by Iran, Hungary, and Spain, respectively. Iranian samples were most divergent from the Spain and Hungary sequences. Pairwise comparisons showed that the highest gene flow was between Türkiye and Hungary, and between Türkiye and Iran, respectively. Phylogenetic analysis grouped the Turkish haplotypes with the Iranian sequences, and Spain was grouped with Hungary. Network analysis revealed that the western Turkish samples were separated from eastern sequences, and all of the eastern Turkish sequences were clustered with the Iranian samples meanwhile a western Turkish lineage provided a source to Hungary and then to Spain. Times of divergence analysis estimated that the Turkish lineage split from the Iranian lineage around 4,67 million years ago, and Hungarian and Spanish lineages diverged from each other about 3 million years ago. Correspondingly, our analyses suggested that Anatolia played a key role as a bridge between the Asian and European populations of C. quercus.

Extreme acidity in a cynipid gall: a potential new defensive strategy against natural enemies.

The morphology of insect-induced galls contributes to defences of the gall-inducing insect species against its natural enemies. In terms of gall chemistry, the only defensive compounds thus far identified in galls are tannins that accumulate in many galls, preventing damage by herbivores. Intrigued by the fruit-like appearance of the translucent oak gall (TOG; Amphibolips nubilipennis, Cynipidae, Hymenoptera) induced on red oak (Quercus rubra), we hypothesized that its chemical composition may deviate from other galls. We found that the pH of the gall is between 2 and 3, making it among the lowest pH levels found in plant tissues. We examined the organic acid content of TOG and compared it to fruits and other galls using high-performance liquid chromatography and gas chromatography-mass spectrometry. Malic acid, an acid with particularly high abundance in apples, represents 66% of the organic acid detected in TOGs. The concentration of malic acid was two times higher than in other galls and in apples. Gall histology showed that the acid-containing cells were enlarged and vacuolized just like fruits mesocarp cells. Accumulation of organic acid in gall tissues is convergent with fruit morphology and may constitute a new defensive strategy against predators and parasitoids.

Antioxidant and Antibacterial Activity of Four Tannins Isolated from Different Sources and Their Effect on the Shelf-Life Extension of Vacuum-Packed Minced Meat.

Four tannin samples extracted from chestnut wood (tannin oenologique, TO), grape (tannin VR grape, TVG), oak gall (tannin galalcool, TG), and oak tree (tannin VR supra elegance, TE) were evaluated for antioxidant and antibacterial activity. The highest total phenolic content (TPC) values were observed in the order of TVG > TG > TE > TO (p < 0.05). The antioxidant activities of all samples were determined in terms of DPPH radical scavenging activity, reducing power, metal-chelating activity, and linoleic acid peroxidation assay. The antioxidant activities of all samples vary and no correlation was observed with the respective TPC values of each sample. Antibacterial activities indicate that all samples showed more or less inhibitory effects against selected Gram-positive and Gram-negative bacteria. Based on antioxidant and antibacterial activity, TO and TVG were selected for the beef mince quality preservation study during refrigerated storage. Both TO and TVG at two different concentrations, 0.25 and 0.5%, could cease the chemical and microbial changes as compared to the control sample. Although total viable count (TVC) did not show a significant difference, the H2S-producing bacteria count was lower in all samples treated with TO and TVG compared to sodium metabisulfite (SMS) and the control sample (p < 0.05). Therefore, TO and TVG could be promising natural food preservatives during refrigerated storage.

The Trojan Women: A Comic

What is right with this “comic” of Euripides's timeless and irreplaceable drama, The Trojan Women, is what was always right about a play that is relentlessly relevant. Carson's translation, spare and clear, distills the language of the original but keeps what is important, including some mouth-puckeringly wry lines. There is barbed wit and heartbreaking lullaby, sometimes coinciding on one page. Thus, the chorus comments, “Troy, you made a bad deal: / ten thousand men for a single coracle of cunt appeal.” In the middle of the same page, the Greek herald Talthybius addresses Hector and Andromache's infant son Astyanax, whom he has come to carry off so that the baby can be thrown from the battlements: “Come along, little mushroom, / little rootlet, little sip, little milk fly, little asterisk, little welkin, / little silhouette, little sugar bubble—/ let go of your mother. / She's broken.” Then lower down on the same page: “It's time for your infinite leap / as decreed by the vote of men. / Take him. / The man to transact things like this / is one who doesn't know pity.”What is wrong with this new rendering is Bruno's awkward, amateurish drawings. Yes, the chorus are all animals, as are all the main characters except mad Cassandra (a partial exception might be made for Menelaus, who is some kind of machine); but Bruno is no Art Spiegelman, and this is no Maus. Spiegelman's cats, pigs, and mice make perfect sense and are elegantly and clearly depicted; they add resonance to the story without raising further questions. In this Trojan Women, it makes sense that Hecuba is an old bitch or Helen a svelte fox in high heels. Poseidon, a wave: okay. But Talthybius, a colossal raven? Athena, “a big pair of overalls, carrying an owl mask in one hand”? Andromache, “a poplar tree with trunk split and roots dragging out the back of the cart”? The infant Astyanax whom Andromache cradles in one Ent-like arm looks more like a cocoon or a hornet's nest or a hypertrophied oak gall than anything else. Menelaus, when he arrives, is “some sort of gear box, clutch or coupling mechanism, once sleek, not this year's model.” These surreal leaps might well work on the stage or screen, but the need to explain them in the text shows how uncomfortably they fit into the story. Carson's explanations, of course, constitute her only significant departures from Euripides.We do not need Bruno's drawings; Carson's pared-down text might work quite well on its own. But even grant the hypothetical that these drawings are an organic and crucial part of this version's vision, then the drawings should not need to be explained. Less would be more. What this version of the classic drama gains in succinctness it loses in tonal clarity—having said which, I would still like to try it out on my students, who might help me to change my mind. Does this retelling of the story remain heartrending and cruel, suffused with irony, sharpened by flashes of wit? Yes. Was it worth the experiment of turning the tragedy into a comic? Sure. Is this uneasy mix of verbal mastery and wobbly draftsmanship the ultimate version of The Trojan Women? Nope.

Plant Gall Diversity in Burned Semi-natural Grasslands in Japan

We surveyed woody plants, including oaks and chestnuts (Quercus L. and Castanea Mill.), and recorded the inhabiting galls induced by oak gall wasps (Hymenoptera: Cynipidae: Cynipini) at seven Japanese semi-natural grassland sites maintained by traditional regular burning with two of the seven abandoned grassland areas. Woody plants were established in all burned and abandoned grasslands. Oak species were found at four of the seven sites. In total, 15 types of cynipid galls were recorded at all four sites where oak species were found. However, the occurrence of species was site-specific for host trees and cynipid galls. Although a few ecological studies of oak gall wasps inhabiting grassland environments, which have rapidly decreased in recent decades, have been conducted, this study suggests that semi-natural grasslands may be potential habitats for oak gall wasps and their host trees, and we provide a checklist of oak gall wasps with host oak records in semi-natural grasslands throughout Japan.

Dependence of the species diversity of oak gall wasps on the physiological heterogeneity of Quercus robur

Dependence of the species diversity of oak gall wasps on the physiological heterogeneity of Quercus robur

Different nest entrance architecture by Colobopsis and Temnothorax ants colonizing oak galls

Different nest entrance architecture by Colobopsis and Temnothorax ants colonizing oak galls

Nest structure, associated parasites and morphology of mature larvae of two European species of Pseudoanthidium Friese, 1898 (Hymenoptera, Megachilidae)

The bee genusPseudoanthidiumis represented by nine species in Europe. Of these nine species,Pseudoanthidium nanumis the most widespread, occurs mainly in xerothermic open habitats and creates nests in various cavity types. In this study, we provide information on the nest structure of this species in reed stalks and oak galls and about its parasitic species. We provide the first report ofP. nanumas a host ofXylophrurus augustus(Ichneumonidae). The biology of the much rarer related speciesPseudoanthidium tenellumis described here for the first time. This species occurs in terrestrial reed beds and wet meadows with the presence of reed galls and flowering plants in the family Asteraceae and is rare throughout its entire distribution area. This species nests inside reed galls induced byLiparafrit flies, and the nest structure is very similar to that ofP. nanum. We report new parasitic species of this bee, namely, the cuckoo beeStelis punctulatissima, the predator-inquilineGasteruption nigrescensand two parasitoids,Leucospis biguetinaandMiltogramma punctata. This bee collects pollen mainly from wetland plants inBidensandPulicaria. We also describe mature larvae of both species. The larvae do not differ greatly from one another; only the shape of mandibles and sclerotisation of mouthparts are slightly different. Further research should address the ecological requirements ofP. tenellum, a poorly understood reed gall inquiline.

Latitudinal gradient in species diversity provides high niche opportunities for a range-expanding phytophagous insect.

When species undergo poleward range expansions in response to anthropogenic change, they likely encounter less diverse communities in new locations. If low diversity communities provide weak biotic interactions, such as reduced competition or predation, range-expanding species may experience high niche opportunities. Here, we investigated if oak gall wasp communities follow a latitudinal diversity gradient (LDG) and if lower diversity communities provide weaker interactions at the poles for a range-expanding community member, Neuroterus saltatorius. We performed systematic surveys of gall wasps on a dominant oak, Quercus garryana, throughout most of its range, from northern California to Vancouver Island, British Columbia. On 540 trees at 18 sites, we identified 23 oak gall wasp morphotypes in three guilds (leaf detachable, leaf integral, and stem galls). We performed regressions between oak gall wasp diversity, latitude, and other abiotic (e.g. temperature) and habitat (e.g. oak patch size) factors to reveal if gall wasp communities followed an LDG. To uncover patterns in local interactions, we first performed partial correlations of gall wasp morphotype occurrences on trees within regions). We then performed regressions between abundances of co-occurring gall wasps on trees to reveal if interactions are putatively competitive or antagonistic. Q. garryana-gall wasp communities followed an LDG, with lower diversity at higher latitudes, particularly with a loss of detachable leaf gall morphotypes. Detachable leaf gall wasps, including the range-expanding species, co-occurred most on trees, with weak co-occurrences on trees in the northern expanded region. Abundances of N. saltatorius and detachable and integral leaf galls co-occurring on trees were negatively related, suggesting antagonistic interactions. Overall, we found that LDGs create communities with weaker associations at the poles that might facilitate ecological release in a range-expanding community member. Given the ubiquity of LDGs in nature, poleward range-expanding species are likely moving into low diversity communities. Yet, understanding if latitudinal diversitypattern provides weak biotic interactions for range-expanding species is not well explored. Our large-scale study documenting diversity in a related community of phytophagous insects that co-occur on a host plant reveals that LDGs create high niche opportunities for a range-expanding community member. Biogeographical patterns in diversity and species interactions are likely important mechanisms contributing to altered biotic interactions under range-expansions.

Andricus protuberans Pujade-Villar &amp; Ferrer-Suay IS A SEXUAL FORM (HYM., CYNIPIDAE, CYNIPINI)

We describe and illustrate the morphological characters of the male of Andricus protuberans Pujade-Villar &amp; Ferrer-Suay, 2015 (Hymenoptera, Cynipidae), an oak gall wasp species considered an asexual generation in the original description. The reasons for this mistake are discussed, and the variability of this species in the metasomal segments is mentioned.