Search

Gall-inducing organisms change the development of their host plant organs, resulting in ontogenetic patterns not observed in the non-galled plants. Distinct taxa induce galls on Schinus spp., manipulating meristematic patterns in the host plant in distinct ways. Here we report ontogenetic novelties induced in the lateral buds of S. engleri by Eucecidoses minutanus, a Cecidosidae, whose galls have been poorly understood.The anatomy, histochemistry, and histometry of galls in distinct phases of development, non-galled buds, and stems of Schinus engleri were analyzed in parallel with the instars of E. minutanus to detail the morphogenetic changes in the host with each larval stage.Ontogenetic phases of the galls were intricately associated with larval development. First and second-instar larvae induced pericycle and pith cells to dedifferentiate into the gall inner meristem, where hyperplasia and cell hypertrophy characterized the growth and development phase of the gall. The innermost layers were lipid-rich nutritive cells that lined the larval chamber. Additional vascular bundle rows were produced in young galls. Third and fourth instar-larvae were associated with the gall maturation phase: centripetal lignification of the outer parenchyma cell layers, epidermal stratification, and activation of a cambium-like meristem (CLM). The CLM activity resulted in new layers of nutritive cells that differentiated inward as the first layers of nutritive cells were consumed by E. minutanus larvae, and, also, in more parenchyma cell layers that formed outward. All tissues between the innermost layer of nutritive tissue that surround the gall chamber and the outermost layer of the dermal system that externally covers the gall form the gall wall, and increased in thickness until the end of gall maturation.E. minutanus induces a structurally complex globoid stem gall, modifying all host plant tissues and stimulating a novel meristematic pattern in S. engleri. The gall developmental stages are each related to specific gall-inducing instars, as gall development progresses according to the development of E. minutanus.

Agrobacterium tumefaciens is a bacterial pathogen that causes crown gall disease on a wide range of eudicot plants by genetic transformation. Besides T-DNA integrated by natural transformation of plant vegetative tissues by pathogenic Agrobacterium spp., previous reports have indicated that T-DNA sequences originating from an ancestral Agrobacterium sp. are present in the genomes of all cultivated sweet potato (Ipomoea batatas) varieties analyzed. Expression of an Agrobacterium-derived agrocinopine synthase (ACS) gene was detected in leaf and root tissues of sweet potato, suggesting that the plant can produce agrocinopine, a sugar-phosphodiester opine considered to be utilized by some strains of Agrobacterium spp. in crown gall. To validate the product synthesized by Ipomoea batatas ACS (IbACS), we introduced IbACS into tobacco under a constitutive promoter. High-voltage paper electrophoresis followed by alkaline silver nitrate staining detected the production of an agrocinopine-like substance in IbACS1-expressing tobacco, and further mass spectrometry and nuclear magnetic resonance analyses of the product confirmed that IbACS can produce agrocinopine A from natural plant substrates. The partially purified compound was biologically active in an agrocinopine A bioassay. A 16S ribosomal RNA amplicon sequencing and meta-transcriptome analysis revealed that the rhizosphere microbial community of tobacco was affected by the expression of IbACS. A new species of Leifsonia (actinobacteria) was isolated as an enriched bacterium in the rhizosphere of IbACS1-expressing tobacco. This Leifsonia sp. can catabolize agrocinopine A produced in tobacco, indicating that the production of agrocinopine A attracts rhizosphere bacteria that can utilize this sugar-phosphodiester. These results suggest a potential role of IbACS conserved among sweet potato cultivars in manipulating their microbial community. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

As an endemic fruit tree in China, the Chinese dwarf cherry (Cerasus humilis (Bge.) Sok.) has substantial ecological and economic value. In 2018, characteristic symptoms of the crown gall of the Chinese dwarf cherry were observed in a nursery base located in Ningxia Hui Autonomous Region, China. The occurrence of the disease among seedlings was observed to be 9.48%. Diseased plants were collected and brought to the laboratory for the isolation of the pathogens. In this study, the isolates were identified by a combination of morphological, biochemical, pathogenicity-related, as well as molecular methods. The isolated strains were white, circular, domed, and glistening. Using 16S rRNA gene sequence analysis and biochemical tests, five strains were identified as Agrobacterium tumefaciens/ biovar 1. Polymerase chain reaction (PCR) was used to detect pathogenicity-associated genes in isolates through the amplification of the partial nucleotide sequences of tms2, virD2 and ipt genes, which proved that the isolates contained the Ti plasmid. In the pathogenicity assay, the crown gall symptom developed on the young stem of tomato and sunflower after inoculation. Based on its morphological, biochemical, pathogenicity and genetic characteristics, the pathogen of the Chinese dwarf cherry crown gall was identified to be A. tumefaciens/ biovar 1.

Callus like galls were observed inside the stem of more than 5-year old papaya trees in Kerala, India. The bacterium Pantoea dispersa and the fungus Fusarium spinosum were isolated from these galls...

Twenty-three species of Tetrastichinae (Chalcidoidea, Eulophidae) in the genera Aprostocetus, Sigmophora and Quadrastichus are reported as parasitoids of gall-inducing Cecidomyiidae (Diptera) from collections mainly from Kent, England. Information on hosts, emergence periods and the sex ratio are given for each species.

The monotypic genus of horn-headed thrips, Eurynothrips Bagnall, had not been seen since its discovery in the early 1900’s in northern Australia, and nothing is known of its biology. A second species of the genus, E. laheyi sp.n., is described from southern Queensland, inducing galls on the young terminal leaves of the small tree, Planchonella pohlmaniana [Sapotaceae].

The success of the galling insects sharing the same microhabitat depends both on the synchrony of their life cycles with the leaf flushing of the super-host plant and to the asynchrony among their life cycles. The asynchrony of the multivoltine life cycles of Lopesia spp. (Diptera—Cecidomyiidae) is favored by the constant leaf flushing in M. gemmulata, and favors the non-overlapping of gall induction periods. Peculiarly, the univoltine life cycle of the galling Lepidoptera on its stem galls is synchronized to the availability of mature host leaves during the rainy season, which is important for the water potential in host stem branches. The abundance of the Lopesia gall morphotypes follow the phenology of M. gemmulata, which obeys the seasonal pattern of water availability in the neotropical savanna climate.

New information is provided on the galling fauna from oaks in Santa Fe (Cuajimalpa (Mexico City) obtained from collections on Quercus laeta Liebmann, 1854 and Quercus rugosa Nee, 1801 (section Quercus), Quercus crassipes Humboldt and Bonpland, 1809 and Quercus calophylla Schlechtendal and Chamisso, 1830 (section Lobatae). Nine species are cited for the first time: Amphibolips hidalgoensis Pujade-Villar and Melika, 2018 and Amphibolips fusus Kinsey, 1937; Andricus fusciformis Pujade-Villar, 2014 and Andricus guanajuatensis Pujade-Villar, 2013; Femuros lusum Kinsey, 1937 and Femuros repandae Kinsey, 1937; Kokkocynips doctorrosae Pujade-Villar and Melika, 2013; Loxaulus hyalinus Pujade-Villar and Melika, 2014; and Neuroterus fusifex Pujade-Villar, 2016. Of the 12 species originally described from Santa Fe, nine of them are only known in this studied area: Amphibolips cibriani Pujade-Villar, 2011; Andricus breviramuli Pujade-Villar. 2014; Andricus rochai Pujade-Villar, 2018; Andricus santafe Pujade-Villar, 2013; Disholcaspis crystalae Pujade-Villar, 2018; Loxaulus laeta Pujade-Villar, 2014, Neuroterus eugeros Pujade-Villar, 2018, Neuroterus verrucum Pujade Villar, 2014 and Zapatella polytryposa Pujade-Villar and Fernandez-Garzon, 2020. New hosts are provided for some of the mentioned species. Some galls are shown that could constitute species yet to be described. Of all mentioned species, the gall is described and illustrated, and aspects of its biology, hosts and distribution are commented.

We describe three new genera of cynipid oak gall wasps from the Nearctic: Burnettweldia Pujade-Villar, Melika & Nicholls, gen. nov., Nichollsiella Melika, Pujade-Villar & Stone, gen. nov., and Disholandricus Melika, Pujade-Villar & Nicholls, gen. nov. (Hymenoptera: Cynipidae: Cynipini). Burnettweldia includes five species, B. californicordazi Cuesta-Porta, Melika & Pujade-Villar, sp. nov., B. conalis (Weld), comb. nov., B. corallina (Bassett), comb. nov., B. plumbella (Kinsey), comb. nov., B. washingtonensis (Gillette), comb. nov.. Nichollsiella includes three species, N. arizonica (Cockerell), comb. nov., N. sulcata (Ashmead), comb. nov., and N. puigi Melika, Cuesta-Porta & Pujade-Villar, sp. nov.. Disholandricus includes four species, D. chrysolepidis (Ashmead), comb. nov., D. lasius (Ashmead), comb. nov., D. reniformis (McCracken & Egbert), comb. nov., D. truckeensis (Ashmead), comb. nov. The genus Paracraspis Weld, comb. rev. is re-established with three species, P. guadaloupensis (Fullaway), P. insolens (Weld), and P. patelloides (Trotter). Descriptions, re-descriptions, diagnoses, keys to genera and species are given, including data on DNA sequences, biology, phenology and distribution.

For insect herbivores, a critical niche requirement—possibly the critical niche requirement—is the presence of suitable host plants. Current research suggests that non-native plants are not as suitable as native plants for native herbivores, resulting in decreases in insect abundance and richness on non-native plants. Like herbivores, gall-forming insects engage in complex, species-specific interactions with host plants. Galls are plant tissue tumors (including bulbous or spindle-shaped protrusions on leaves, stems and other plant organs) that are induced by insects through physical or chemical damage (prompting plants to grow a protective tissue shell around the insect eggs and larvae). As such, we hypothesized that gall-inducing insect species richness would be higher on native than non-native plants. We also predicted higher gall-inducing insect species richness on woody than herbaceous plants. We used an extensive literature review in which we compiled gall host plant species by genus, and we assigned native or non-native (or mixed) status to each genus. We found that native plants host far more gall-inducing insect species than non-native plants; woody plants host more gall-inducing species than herbaceous plants; and native woody plants host the most gall-inducing species of all. Gall-inducing species generally are a very cryptic group, even for experts, and hence do not elicit the conservation efforts of more charismatic insects such as plant pollinators. Our results suggest that non-native plants, particularly non-native woody species, diminish suitable habitat for gall-inducing species in parallel with similar results found for other herbivores, such as Lepidopterans. Hence, the landscape-level replacement of native with non-native species, particularly woody ones, degrades taxonomically diverse gall-inducing species (and their inquilines and parasitoids), removing multiple layers of diversity from forest ecosystems.

Ozognathus cornutus(LeConte, 1859) (Coleoptera: Ptinidae: Ernobiinae), species native to North America, is a saproxylophagous species and is known to feed on decaying tissues within conspicuous galls and on vegetal decaying organic material such as dried fruits or small wood shavings and insect excrements in galleries made by other woodboring species. A few years after the first record in 2011, its naturalization in Italy is here reported. The insect was found as successor in galls ofPsectrosema tamaricis(Diptera Cecidomyiidae),Plagiotrochus gallaeramulorum,Andricus multiplicatusandSynophrus politus(Hymenoptera Cynipidae).The galls seem to have played an important ecological role in speeding up the naturalization process. The lowest proportion of galls used byO. cornutuswas recorded forP. tamaricis(23%), the only host belonging to Cecidomyiidae, while the percentages recorded for the other host species, all Cynipidae forming galls on oaks, were higher: 43.6%, 61.1% and 76.9% inA multiplicatus,S. politusandP. gallaeramulorum,respectively. AlthoughO. cornutusis able to exploit other substrates like dried fruits and vegetables, for which it could represent a potential pest, it prefers to live as a successor in woody and conspicuous galls, which thus can represent a sort of natural barrier limiting the possible damages to other substrates.

Gall cytological, metabolic, and structural traits are established due to the feeding habits of the associated galling herbivores, and sometimes are influenced by other organisms involved in the interaction. We tested this assumption on three gall morphotypes, the globoid, the lenticular, and the fusiform, induced by Cecidomyiidae on leaflets of Inga ingoides (Rich.) Willd. (Fabaceae: Caesalpinioideae). Taking for granted that the three Cecidomyiidae galls are induced on the same host plant and organ, we assume that the cytological and histochemical traits of their nutritive cells may be similar, but under the fungi influence, the ambrosia gall cytological profile may be peculiar and reflect on the accumulation of primary metabolites. The ambrosia globoid galls involve three organisms (host plant, gall inducer, and fungi), while the fusiform and the lenticular galls involve two organisms (host plant and gall inducer). The accumulation of primary metabolites is similar among the three gall morphotypes, except for the non-detection of reducing sugars in the fusiform galls. The fungi presence can impact the system but does not define exclusive features for the ambrosia globoid galls when compared to the lenticular and fusiform morphotypes. In fact, the cytological traits have revealed three different cytological mechanisms for food resources availability to the three galling Cecidomyiidae: (a) cell wall destructuring and cell death by fungi intermediation in the ambrosia globoid galls, (b) necrosis-type cell death in the fusiform galls, and (c) maintenance of continuous metabolic activity in the lenticular galls.

Galling insects manipulate host plant tissues for their own benefit. Because of feeding activity of the gall insects, both structural and metabolic changes occur in the host plant, leading to the formation of an abnormal growth of new organ (the gall). Galls induced by Palaeomystella oligophaga (Lepidoptera) on Macairea radula (Melastomataceae) depend on the constant larval feeding stimulus for establishment and development. The gall consists of two tissue compartments – the storage and nutritive tissues. These two gall tissues were investigated here in terms of the levels of oxidative stress and of a possible differential chemical investment. In addition, we investigated the relationship between gall coloration and the concentration of primary metabolites. Our results supported a differential investment of chemical compounds in the M. radula compartments, with higher concentrations of polysaccharides, malondialdehyde, and phenolic compounds in the storage tissue, and higher total soluble sugar concentrations in the nutritive tissue. Regarding gall colour, conflicting results were observed in the present gall system. Water-soluble polysaccharides were detected at higher concentrations in red galls than in green galls. As a water-soluble polysaccharide, pectin seems to be related to increased anthocyanin stability, a process that might occur in galls, leading to red coloration.

In June 2017, deer-horn-like galls covered with a whitish, powdery fungal layer were found on the trunks of Cinnamomum pseudopedunculatum (Lauraceae) in Hahajima, Bonin Islands, Japan. The galls were similar to those of horn gall disease of Ci. tenuifolium caused by Laurobasidium hachijoense (Laurobasidiaceae, Exobasidiales) on Hachijo Island, approximately 700 km north of Hahajima. Based on morphological observation and molecular analyses of ITS and LSU regions, the fungus isolated from the surface of the galls was identified as L. hachijoense. This is the first report of the horn gall disease of Ci. pseudopedunculatum.

Chañar (Geoffroea decorticans- Fabaceae) is a tree from South America that is normally infected with galls originated by insects. One of its parasites is Allodiplosis crassa (Cecidomyiidae, Diptera) which produces globular galls with sticky prolongations. Since this plant has medicinal uses in Argentina, its infestation could alter the quality of the plant drug. The surface of insect-induced galls usually contains defensive features such as trichomes, increased hardness and an increase in the content of polyphenolic compounds. The objective of this research is to assess the structural and histochemical features of the gall and to compare the content of polyphenolic metabolites in the gall, in the healthy leaf and in lignified stems of G. decorticans. The methanolic extract from the galls showed the highest amount of polyphenolic and proanthocyanidins and the lowest amount of hydroxycinnamic derivatives and flavonoids compared to the methanolic extract of the leaves. The photographs taken from the external surface of the gall showed that some prolongations have heads. The histochemical analysis showed that the prolongations have a high amount of proanthocyanidins and flavonoids; and that the heads are reactive to Sudan III. These phytochemical and histological characteristics may have a defensive role against harmful fungi and parasites that attack the larvae of the A. crassa. The results of this study show the presence of defensive features in an insect-induced gall of a medicinal plant with potential implications in the pharmacological activity of this species. This is the first report of a histochemical and phytochemical study in G. corticans galls.

Dryocosmus kuriphilus (Hymenoptera: Cynipidae), the Asian chestnut gall wasp (ACGW), is an invasive pest that threatens native stands and orchards of European Sweet Chestnut (Castanea sativa Mill.). ACGW induces galls in stems, petioles, and midribs. These galls cause inhibition of tree growth and fruit production. An understanding of morphogenetic changes in host organs is important to evaluate how plant resources are redirected to galls. Structural divergences in C. sativa petioles, midribs, and respective galls were investigated. Larvae of D. kuriphilus are found in the central region of young petioles and midribs in the spring. They are positioned in the pith region of petioles and midribs, surrounded by vascular tissues. The increase in cell layers and volume is evident in the ground tissues of galls, i.e., parenchyma, collenchyma, and sclerenchyma that originate from ground meristem. Gall formation causes the separation of the original vascular system into several collateral and amphicribral vascular bundles. The vascular web branching likely favors the redirection of resources from developing leaf blades to the galls by compensatory hydraulic mechanisms. The rapid growth rates of galls are likely supported by an increased water supply to gall sites. Cytoplasmically dense and metabolically active nutritive linings of the larval chambers are the sole source of food for larvae. Nutritive cells are maintained by a rich vascular supply. The redifferentiation of mechanical tissue surrounding the nutritive tissue also requires energy and protects the D. kuriphilus larva until pupation. These vascular alterations impact the normal formation of tissues in distal regions of the leaf, which reduces the productivity of chestnut trees.

The developmental processes of galls are better known when they are induced on vegetative organs, whereas they have hardly ever been described for reproductive ones. Herein, galls induced by Allorhogas uberlandiensis (Hymenoptera) on ovules of Miconia chamissois Naudin (Melastomataceae) were analyzed in terms of morphological, anatomical, histochemical, and cytological characteristics. Galls are induced on the ovules before fertilization, and act as a physiological seed. Therefore, the ovary grows and develops into a fruit-like gall. The ovule-galls are on average 20-times larger than the seeds, and fruit-like gall volume is on average 5.4-times greater than that of mature fruits. These are related to cell hypertrophy and tissue hyperplasia in the host organ. There is a typical nutritive-tissue formation in the ovule-gall with lipid, protein, and pectin storage, as well as a storage tissue close to the epidermis. This nutritive tissue shows a smooth endoplasmic reticulum, multivesicular bodies, and mitochondria-rich cells. After gall induction, all of the ovules degenerate, and the ovary and hypanthium hypertrophy to form the fruit-like gall. The fruit-like galls form a physical barrier blocking the anthesis, thereby preventing fertilization and keeping only ovule-galls. Our study shows that the galling insect A. uberlandensis may reduce the reproductive success of M. chamissois, thus acting as a biological control agent for this host-plant population.

BACKGROUND: Mango (Mangifera indica) is a very important fruit and it is attractive for its delicious aroma and flavor. Mango is susceptible to various types of pathogens that result in decline of its fruit production. An important pathogen, Agrobacterium tumefaciens attacks on mango plant and it causes crown gall disease. The present study was conducted to isolate and identify Agrobacterium tumefaciens from crown gall samples. METHODOLOGY: These samples were collected from BAU campus, Mymensingh. The bacterium was isolated and characterized by morphological, microscopic, biochemical, and confirmed by molecular test. KEY FINDINGS: The morphological, microscopic and biochemical tests initially revealed that all the bacterial isolates are gram negative. Pathogenicity test: a carrot disc bioassay showed tumors in the plant because T-DNA of the bacteria was transferred and integrated into each of carrot disc. Antibiotic sensitivity tests revealed that the resistance to antibiotic. Moreover, DNA was isolated from infected tissue and after gel electrophoresis of PCR product, DNA band with expected 184bp was found and therefore, it was finally confirmed that the isolates were Agrobacterium tumefaciens. CONCLUSION: This bacterium has ability to alter hosts genome, thus, is considered in plant biotechnology as one of the natures best genetic engineer, antitumor studies and researches other purposes. [Fundam Appl Agric 2021; 6(1.000): 43-49]

During studies to investigate the health of mangrove trees in South Africa, high numbers of Avicennia marina were found with leaf galls caused by unidentified adults and larvae of midges (Cecidomyiidae). Fungal fruiting structures were commonly observed on the abaxial areas of the galls. To determine the identity of the fungi associated with the gall midges, phylogenetic analyses using multigene sequence data were used. The nuclear large subunit (LSU), internal transcribed spacer (ITS), and a portion of the actin gene region (ACT), were amplified and analyzed. The results revealed that the fungal fruiting structures represent a new taxon in the Mycosphaerellaceae described here as Zasmidium mangrovei sp. nov. This is the first report of a species in the Mycosphaerellaceae associated with cecidomyiid leaf galls on A. marina.

A new whitefly species, Pealius gallae sp. nov. forming pit galls on Celtis philippensis Blanco discovered in the Andaman Islands, is described and illustrated. Leaf pit galls were formed in the microhabitat of the puparia, each pit was observed with a single puparium, the opposite side of the galls was convex, easily recognizable by chlorotic spots; older galls turn brown and brittle. This is the first authentic record with illustrations of any leaf pit gall forming whitefly. The specialised gall inducing insects may pose extinction risks with limited host range. The new whitefly differs from Pealius cinnamomi David and Sundararaj in the habitus, gall forming nature, number of submarginal setae, vasiform orifice shape, broad tracheal folds and pattern of tubercles in it.

A new species, Dactylodiplosis petibaurum Maia, sp. nov., that induces galls on axillary buds of Ocotea pulchella is described from Brazil (larva, pupa, male, female, and gall), based on material c...

The galls induced by hemipterans generally show hypertrophy of the phloem; these insects usually feed on the sap in the sieve tube elements, occasioning phloem bundle hypertrophy. However, there are some exceptions; for example, the phylloxerids feed on the gall wall parenchyma. It has remained unknown, however, whether Daktulosphaira vitifoliae (the vine phylloxera) also causes hypertrophy of the phloem bundles. The galls induced by D. vitifoliae in leaves of the rootstock variety Richter-110 (Vitis berlandieri × Vitis rupestris) were examined microscopically. D. vitifoliae was found capable of inducing vascular bundle hypertrophy, as well as the nutritional enrichment of the gall wall parenchyma cells upon which the insect feeds. The hypertrophy of the phloem bundles commonly seen in hemipteran-induced leaf galls also occurs in those induced by D. vitifoliae, even though these do not feed on the phloem contents, but rather on the gall wall parenchyma. The appearance of phloem bundle hypertrophy in hemipteran-induced leaf galls requires the remobilization of photoassimilates that might affect the productivity of the affected plant.

Zizania latifolia is a perennial aquatic vegetable, whose symbiosis with the fungus Ustilago esculenta (member of Basidiomycota, class Ustilaginaceae) results in the establishment of swollen gall formations. Here, we analyzed symbiotic relations of Z. latifolia and U. esculenta, using a triadimefon (TDF) treatment and transcriptome sequencing (RNA-seq). Specifically, accurately identify the whole growth cycle of Z. latifolia. Microstructure observations showed that the presence of U. esculenta could be clearly observed after gall formation but was absent after the TDF treatment. A total of 17,541 differentially expressed genes (DEGs) were identified, based on the transcriptome. According to gene ontology term and Kyoto Encyclopedia of Genes and Genomes pathway results, plant hormone signal transduction, and cell wall–loosening factors were all significantly enriched due to U. esculenta infecting Z. latifolia; relative expression levels of hormone-related genes were identified, of which downregulation of indole 3-acetic acid (IAA)-related DEGs was most pronounced in JB_D versus JB_B. The ultra–high performance liquid chromatography analysis revealed that IAA, zeatin+trans zeatin riboside, and gibberellin 3 were increased under U. esculenta infection. Based on our results, we proposed a hormone–cell wall loosening model to study the symbiotic mechanism of gall formation after U. esculenta infects Z. latifolia. Our study thus provides a new perspective for studying the physiological and molecular mechanisms of U. esculenta infection of Z. latifolia causing swollen gall formations as well as a theoretical basis for enhancing future yields of cultivated Z. latifolia. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. 2021

BackgroundGalls or the neoplastic growth on plants result from a complex type of interaction between the inducers (Acari, Insects, Microbes and Nematodes) and plants. The present study sheds light on the gall inducing habit of a highly host specific eriophyid mite,Aceria pongamiae,on the leaves ofPongamia pinnataleading to the production of abnormal pouch like outgrowths on the adaxial and abaxial surfaces of the foliage. Each leaf gall is a highly complex, irregular massive structure, and the formation of which often leads to complete destruction of leaves, especially during heavy mite infestation, and thereby adversely affecting the physiology and growth of the host plant.ResultsThe study was carried out by making comparative observations on FE-SEM histological sections of galls representing four different growth stages categorized on the basis of difference in age groups. Apart from variations in cell metaplasia, a dramatic change was observed in the abaxial-adaxial polarity of the laminar surfaces also throughout the developmental sequence of galls, in all the four growth stages. Significant variations could be observed in the anti-oxidative potency as well as elemental composition in the all the four age groups of galls, and also revealed ATR-FTIR pattern of gall formation.ConclusionBeing the first attempt to unravel the mystery of gall induction by eriophyids in general and byA. pongamiaein particular, on its host plantP.pinnata,by shedding light on the structural and histological alterations taking place during leaf gall formation under the influence of the mite, the current study is to be treated as the model of plant-animal interactive system.

Gall‐inducers can be considered ecosystem engineers when they modify leaf morphology and create shelters for secondary users, altering properties of ecological communities. In this study, we evaluated whether shelter structures created by leaf‐galling contribute to changes in the diversity and composition of the community at plant and leaf scales, the effects of leaf roll occupation on the choice of secondary colonisers and the influence of leaf shelters on herbivory levels on host plants. The arthropod abundance, richness, and biomass were higher in leaf shelters compared to intact leaves. These effects were observed at similar magnitudes at both plant and leaf scales. The composition of arthropods differed between plants with leaf‐rolled galls and plants with galls removed and between unoccupied leaf rolls and intact leaves. Artificial leaf rolls increased arthropod abundance, richness, and biomass by almost 100.0% compared to intact leaves. However, occupied artificial leaf rolls had a decrease in abundance, richness, and biomass of arthropods by almost 60.0% compared to unoccupied leaf rolls. Finally, plants with galls removed exhibited higher levels of leaf herbivory than plants with leaf‐rolled galls. Our findings demonstrated the strong and positive indirect effects of gall induction facilitating shelter creation and the indirect effects of shelters on the diversity, species composition, and on leaf herbivory, and should be replicated in other systems involving plants and their respective gallers.

The review considers quarantine species and nematode pathotypes potentially dangerous for domestic potato production. Potatoes are affected by more than 30 types of parasitic nematodes, but the review focuses on the most harmful representatives of genera that cause great damage to potato production: Globodera, Ditylenchus, Nacob bus and Meloidogyne. Phytopathological and molecular methods of identification of species and pathotypes and the main achievements in studying the population variability of parasitic potato nematodes were analyzed. It was shown that due to the peculiarities of the life cycle of nematodes and lability of their genomes, the genetic variability of these organisms is very high, which creates a threat of forming new pathogenic genotypes of the parasites. The information about the intra- and interpopulation variability of nematodes is important for studying the ways of introduction and distribution of separate species, as well as for searching for the correlations of molecular markers with the pathotype. Phylogenetic studies based on modern data on genetic variability of populations have allowed to reveal species complexes in Globodera pallida (Stone) Behrens and Nacobbus aberrans (Thorne) Thorne & Allen (sensu lato), including cryptic species. The main components of successful protection preventing a wide distribution of parasitic nematodes are quarantine measures, agricultural techniques, biological methods of protection and cultivation of resistant cultivars. Special attention in the review is paid to the breeding of potato cultivars with durable resistance to various nematode pathotypes, because the cultivation of such varieties is the most ecologically safe and economically advantageous way to prevent epiphytoties. Currently, significant progress has been made in the genetic protection of potato cultivars, especially against cyst-forming nematodes. The review provides data on sources of potato resistance to parasitic nematodes identified in collections of wild and cultivated species. Data on identified R-gens and QTL of resistance that have been introduced into breeding varieties using different methods and approaches are analyzed. The literature data on the study of structural and functional organization of genes for resistance to potato cyst nematodes are given. The results of molecular research on revealing the polymorphisms of loci involved in the control of resistance to cyst and gall nematodes, the development of molecular markers of certain genes and their use in marker-assisted selection for developing of new resistant cultivars, including those with group resistance, are considered.

Larvae of a previously undescribed gall midge species have been feeding within malformed flower buds of goji berry Lycium barbarum L. (Solanaceae) in China, preventing fruit development and causing damage to the fruit industry. The new species is named Gephyraulus lycantha Jiao & Kolesik, its morphology is described, the COI mitochondrial gene segment is sequenced, and the biology is outlined. In order to taxonomically accommodate the new gall midge, the scope of the genus Gephyraulus is broadened and now encompasses also species that lack dorso-apical sensoria on the female cercus. LSID: urn:lsid:zoobank.org:pub:17B243CF-5235-405B-AA60-8E872C848367.

Genus Aprostocetus is recorded from Korea for the first with the description of a new species: Aprostocetus cumgallae sp. nov. This species is an inquiline of Rhopalomyia giraldii inducing cottony galls on Artemisia princeps. We revealed this species is an inquiline by rearing and gall dissecting. We herein describe and illustrate the new species, its color variations and give some biological information. www.zoobank.org/urn:lsid:zoobank.org:pub:0210CE57-4C8A-4A64-9175-E3F5F8748DC5 .

Aprostocetus smilax Gates & Zhang, sp. nov., is described from stem and leaf galls on Smilax havanensis Jacq. in southern Florida, USA. It is the third species of Aprostocetus Westwood known to induce plant galls. Two parasitoids of A. smilax are also described: Phylloxeroxenus smilax Gates & Zhang sp. nov. and Sycophila smilax Gates & Zhang, sp. nov. We conclude that A. smilax is the true gall inducer on Smilax L., and thus the host records of Diastrophus smilacis Ashmead and its inquiline Periclistus smilacis Ashmead, both from Smilax, are erroneous.

The gall fly, Urophora stylata, was released in New Zealand in 1998 as a biocontrol agent for the thistle weed, Cirsium vulgare (Scotch thistle). In the summer of 2018, a survey was conducted to assess the field host range of the biocontrol agent in New Zealand. A random selection of 18 pasture populations under sheep and/or beef production, where C. vulgare was present, was surveyed to quantify the attack intensity (gall size relative to seedhead size) on C. vulgare, and the presence of attack on other thistle weeds within the same population. At each location, seedheads were collected from C. vulgare and all other thistle species (Cardueae) present, which included Cirsium arvense (Californian thistle), Cirsium palustre (marsh thistle), Carduus nutans (nodding thistle), and an Arctium species (burdock). In addition to attack on C. vulgare, the gall fly was recorded on C. arvense (at six locations) and C. palustre (at one location). The probability of the presence of attack on C. arvense was positively correlated with the attack intensity on C. vulgare, suggesting that attack on C. arvense is a ‘spill-over effect’ occurring where seedheads of C. vulgare are in limited supply.

Supporting Information: Table S1. Species specific primers and their annealing temperatures for the hymenopteran species associated with Leptocybe invasa galls and the expected fragment sizes amplified by each species‐specific primer for the region Cyt b. Table S2. The fragment sizes of digested Cyt b amplicons using the AseI restriction enzyme for Leptocybe invasa (A and B), Selitrichodes neseri, Megastigmus zebrinus, Megastigmus pretorianensis and Quadrastichus mendeli.

Several hypotheses have been proposed to explain the distribution pattern and abundance of herbivorous insects on its host plants. For example, the plant architecture hypothesis predicts that variation in host plant architecture influences insect herbivore community structure, dynamics and performance. This study aimed to test the plant architecture hypothesis and its relation with gall abundance on two Brazilian endemic plant species, Clusia lanceolata (Clusiaceae) and Monteverdia obtusifolia (Celastraceae) in Marica Restinga, Rio de Janeiro. Plant architecture and gall abundance were directly recorded on 30 individuals from each plant species. Plant height, soil height circumference, number of second and third level ramifications, treetop area, plant volume, and leaf number were all used as predicting variables of gall abundance. A total of 922 insect galls were registered on C. lanceolata and 1.139 on M. obtusifolia . Variations on plant architecture did not explain gall abundance for both plant species. Results can be explained the plastic potential of the species studied. In this sense, the morphological changes in C . lanceolata and M. obtusifolia caused by the galls may have been buffered to maintain the vigor of the species. The difference between the variables in relation to gall abundance indicates that species studied can tolerate and minimize the presence of galling insects, revealing a high capacity for homeostasis in the face of biotic stress.

A gall midge (Diptera, Cecidomyiidae) is reported here for the first time from spikelets of Cortaderia selloana, a prominent alien invasive grass species in southern Europe. The insect is described as a new genus and species, Spanolepis selloanae Gagne. Based on morphological and molecular analyses, the new genus and species are tentatively placed within the supertribe Lasiopteridi and tribe Dasineurini. Its effects on seed production were studied in order to ascertain its effectiveness in limiting sexual reproduction of the invasive plant species. The larvae of S. selloanae feed on the ovaries with a mean seed depletion of 74% in the studied population in northwest Spain. The new species is a potential candidate agent for the effective biological control against C. selloana.

The origin of xylem cells, intracellular variation, and gall position relative to the host plant organ are related to mechanisms that positively compensate hydraulic conductivity in galls. Gall position in its host organ may be determinant for the new patterns of xylem differentiation. Leaf galls may be attached to the host leaf by a peduncle, as the extralaminar galls, or may develop in a morphological continuum with their host organ, as the intralaminar galls. Due to these two distinct positions and the related patterns of cell differentiation, gall vascular cells and tissues may vary in area and size, which were investigated in the structural features of the vessel elements in galls and in their connections with their host leaflets in three gall morphotypes associated to Inga ingoides. Also, as phytohormones orchestrate the differentiation of vascular cells, the sites of accumulation of auxins and cytokinins were detected by histochemical techniques. Besides aspects of cell differentiation, cytometric and histometric xylem features, as well as the relative water content were evaluated looking for compensatory mechanisms related to hydraulic status of the galls and the gall constriction hypothesis. The detection of auxins was related with the differentiation of new vascular cells. The origin of xylem cells, intracellular variation, and gall position relative to the host plant organ are related to mechanisms that positively compensate the hydraulic conductivity in galls. Extralaminar galls develop as appendages of adventitious origin, which theoretically imply in rupture with the host leaf ontogenetical pattern. Based on the fact that gall position influences xylem cell features, the gall-constriction hypothesis was revisited with leaflet galls as models of study, but was corroborated just for the intralaminar galls.

The nutritive tissues of galls induced by Ditylenchus gallaeformans (Nematoda) have promeristematic capacity, which may turn these galls into sinks of Al on their Melastomataceae Al-accumulating hosts. Such a sink of Al may affect gall growth and mineral nutrient intake. Based on the fact that galls are good models for plant developmental studies, we aimed to understand how Al-accumulating host plants in the Cerrado environment deal with Al toxicity in subcellular levels. Here, we used the ICP-OES method to check the variations on mineral nutrients, and the morin, hematoxylin, and Prussian blue stainings for Al and Fe histolocalization in galls induced on four Miconia species of the Brazilian Cerrado. We confirmed the new Al-accumulating feature for two Miconia species of the Cerrado environment. Furthermore, we found that Al accumulates in lesser concentrations in gall tissues than in non-galled tissues of the Miconia hosts. Staining methods indicated that the polyphenols avoid Al-binding to the apoplast and the nucleolus of the promeristematic cells, and mediated its binding to parenchyma cell walls. As well, we inferred that Fe3+ is transported by xylem and stored in gall parenchyma, where it is reduced to Fe2+, being available in gall nutritive cells. Our results demonstrated an Al compartmentalization between the apoplast and symplast of the inner cell layers in galls, as well as indicated the phenolics action against Al-toxicity and toward Fe availability for the diet of Ditylenchus gallaeformans.

The eriophyoid mite Aceria massalongoi (Canestrini) was collected from globoid leaf galls on severely injured chaste trees, Vitex agnus-castus L. (Lamiaceae), in Bari and Bernalda (southern Italy), and on the Ionian island Leukade (Greece). Female, male and nymph were described in detail, following the current morphometric descriptive scheme, supplementing older and incomplete descriptions. Molecular characterization of A. massalongoi from Italy and Greece was conducted by amplifying and sequencing the ribosomal ITS, the D2-D3 expansion domains of the 28S rRNA gene and the mitochondrial COI, for the first time. Phylogenetic trees based on the three molecular markers showed congruent results, confirming that Italian and Greek A. massalongoi populations are the same species that cluster together with some intraspecific variability. Galls, ranging from 0.5 to 2.8 mm in diameter, were randomly distributed on both leaf surfaces, and protruded ca. 1 mm from the leaf surface. Sometimes they were closely aggregated on midrib and leaves, which, consequently, appeared strongly deformed. Close-up observations revealed that gall induction causes hyperplastic proliferation of leaf tissues around the gall chamber hosting mites. The uniserial cell lining inside this chamber provides the nutritional tissue for the mites. All feeding cells contained one or more (frequently 2-3) hypertrophied nuclei and dense granular cytoplasm.

Trioza turougueisp. nov., a new species of jumping plant lice (Hemiptera, Triozidae) from Taiwan, is described and illustrated based on adults and immatures. The latter induce pea-shaped galls on the stems of Cinnamomum osmophloeum Kaneh. (Lauraceae). The gall phenology of the new species is described. A list of species of Triozidae associated with Cinnamomum in the Old World is provided. The following nomenclatorial acts are proposed: Trioza inflata Li, 1992 = Trioza xiangicamphorae Li, 1992, syn. nov.; Siphonaleyrodes formosanus Takahashi, 1932, stat. rev., is removed from synonymy with Trioza cinnamomi (Boselli, 1931).

In situ preservation of fossil insect damage in plant fossils is an excellent tool to study the coevolution of flora and fauna through geological time, but finding both damage and the insect causing that damage in the same specimen is a very rare phenomenon. Galling is a common form of angiosperm leaf damage, which can be regarded as a kind of extended phenotype of the causal insects, essentially the gall midges, but galls usually lack remains of the insects themselves. Here we report the in situ occurrence of a gall midge (Insecta, Diptera, Cecidomyiidae) as well as its pupal exuviae on the abaxial cuticular surface of fossilized leaf cuticle fragments of Fabaceae leaves (cf. Albizia) that also bear galls, recovered from the latest Neogene (Rajdanda Formation, Pliocene) sediments of the Chotonagpur Plateau, Jharkhand, northeastern India. This Pliocene gall midge features well-preserved legs, segmented antenna with distinct and enlarged scape, elongate curved setae, and longer than broad terminal plate of the ovipositor lamellae. The in situ presence of a gall midge on a host fabaceous leaf cuticle indicates the existence of a host-ectoparasite relationship in the ancient warm and humid tropical monsoon-influenced forests of eastern India during the Pliocene. This is the first authentic fossil record of an in situ phytophagous insect of Cecidomyiidae from India, as well as southeast Asia. Although the identification of the recovered phytophagous insect associated with the fossil leaf cuticle is only possible to family level, this find reveals that such plant-insect relationships existed in the Pliocene of eastern India.

In the last years, an insect is detected on the foliage of Quercus ilex trees in Algeria (North-East region). Dryomyia lichtensteini F.Löw, 1878 (Diptera: Cecidomyidae), The Chronology of Gall’s emergence of Dryomyia lichtensteini and its field infestation rate were followed since 2014, in evergreen oak plantation in the Algerian North-East Region (Setif). Some statistical methods of Gall’s emergence of this pest and its effect at Quercus ilex’s Sanitary state are reviewed and discussed. For each study area (North-South-East-West), 10 trees were marked. 30 leaves of each tree were removed, so it is 300 leaves for each site, which were analyzed. This study is based on the number of galls observed. In order to highlight the degree of attack of pests. The outputs were made from November 2014 to November 2016, due to one output per month. Keywords: Quercus ilex, Cecidomyidae, gall inducers, Algeria