Field and Laboratory Observations on the Biology of Aceria angustifoliae with Emphasis on Emergence of Overwintering Mites.

Data on the life strategy of A. angustifoliae (population fluctuation in buds and on leaves, emergence and migration to the overwintering sites), as well as its temperature-dependent emergence from overwintering sites at constant temperatures, were determined. The eriophyid mite overwintered into buds and the density of active mites inside them from winter 2017 to spring 2018 was higher than that in winter 2018-spring 2019. In the second half of March 2018 and in winter 2018-spring 2019, the mite density inside the buds decreased gradually with a peak of emergence occurring at the beginning of plant blossoming. Population density on leaves increased in summer, reaching a higher and later peak in 2018, and gradually decreased in autumn with mites migrating to overwintering sites. A lower developmental threshold of 4.5 °C was calculated. About half of the mite population was estimated to emerge from the overwintering sites at an accumulation of degree days ranging, on average, between 85.5 (at 20 °C) and 104.4 (at 10 °C) degree days above the assessed threshold.

Integrative Taxonomy and Synonymization of Aculus mosoniensis (Acari: Eriophyidae), a Potential Biological Control Agent for Tree of Heaven (Ailanthus altissima).

The taxonomy of Aculus mosoniensis appears to be an unresolved question and its clarification is required, owing to the potential relevance of this mite species as a biological control agent of the tree of heaven. This paper is aimed at giving accurate details on a previously and shortly announced synonymization with Aculops taihangensis, using a morphological and molecular approach. A fusiform morph of A. mosoniensis was distinguished from a vermiform morph and this latter was recognized as deutogyne, which was herein documented. Phylogenetic relationships between Chinese Ac. taihangensis and all A. mosoniensis mites collected in twenty localities in Europe were examined through the analysis of the mitochondrial cytochrome c subunit I (CO1) protein and the nuclear ribosomal internal transcribed spacer 1 region (ITS1). CO1 sequences of Ac. taihangensis from the Shandong province in China and those from mites collected in Austria and Slovenia were 100% identical; the ITS1 sequence of an Ac. taihangensis paratype matched for 99.8% with those obtained from protogynes and deutogynes of A. mosoniensis collected in Italy. All these data supported the announced synonymization of A. mosoniensis with Ac. taihangensis. Aculusmosoniensis was found genetically variable, with five CO1 haplotypes in Europe (becoming eight along with those of Ac. taihangensis) clustering in two highly supported maternal lineages and eight ITS1 haplotypes (becoming nine along with those of Ac. taihangensis) distributed in four supported clades. No overlap between intra- and interspecies distances was observed for both markers and all studied A. mosoniensis populations clustered in one monophyletic mitochondrial clade, suggesting that only one single species might occur in Europe. However, more mite clades may be related to more tree of heaven biotypes with potential ecological differences, which might have potential effects on the biological control and should be investigated.

The first annotated checklist of Pentatomoidea (Hemiptera: Heteroptera) fauna of Alta Murgia National Park (Apulia region, Southern Italy).

Information regarding Pentatomoidea is scarce in Southern Italy, and in particular concering the Apulia region (Sourthern Italy), an area of high biodiversity potential. We conducted an extensive survey of Pentatomoidea fauna in the Alta Murgia National Park, a Site of Community Importance, and neighbouring areas located in central part of Apulia region. The survey was carried out in 2016, 2017 and 2020, sampling different habitat types. We found 55 species, with five new records for Apulia: Solenosthedium bilunatum, Acrosternum millierei, Sciocoris homalonotus, Cyphostethus tristriatus and Holcogaster fibulata. The polyphagous pest Halyomorpha halys was found only in urban areas, whereas Ventocoris falcatus, Ellipsocoris kalashiani and Tholagmus flavolineatus, considered rare species, were collected in dry grasslands, confirming the crucial role of natural habitat for biodiversity conservation.

Field Assessment of the Host Range of Aculus mosoniensis (Acari: Eriophyidae), a Biological Control Agent of the Tree of Heaven (Ailanthus altissima).

Tree of heaven (Ailanthus altissima) is a fast-growing deciduous tree native to China, considered a serious invasive species worldwide, with several socio-economic and ecological impacts attributed to it. Chemical and mechanical methods have limited efficacy in its management, and biological controls may offer a suitable and sustainable option. Aculus mosoniensis (Ripka) is an eriophyid mite that has been recorded to attack tree of heaven in 13 European countries. This study aims to explore the host range of this mite by exposing 13 plant species, selected either for their phylogenetic and ecological similarity to the target weed or their economic importance. Shortly after inoculation with the mite, we recorded a quick decrease in mite number on all nontarget species and no sign of mite reproduction. Whereas, after just one month, the population of mites on tree of heaven numbered in the thousands, irrespective of the starting population, and included both adults and juveniles. Significantly, we observed evidence of damage due to the mite only on target plants. Due to the specificity, strong impact on the target, and the ability to increase its population to high levels in a relatively short amount of time, we find A. mosoniensis to be a very promising candidate for the biological control of tree of heaven.

Eriophyid Mites in Classical Biological Control of Weeds: Progress and Challenges.

A classical biological control agent is an exotic host-specific natural enemy, which is intentionally introduced to obtain long-term control of an alien invasive species. Among the arthropods considered for this role, eriophyid mites are likely to possess the main attributes required: host specificity, efficacy, and long-lasting effects. However, so far, only a few species have been approved for release. Due to their microscopic size and the general lack of knowledge regarding their biology and behavior, working with eriophyids is particularly challenging. Furthermore, mites disperse in wind, and little is known about biotic and abiotic constraints to their population growth. All these aspects pose challenges that, if not properly dealt with, can make it particularly difficult to evaluate eriophyids as prospective biological control agents and jeopardize the general success of control programs. We identified some of the critical aspects of working with eriophyids in classical biological control of weeds and focused on how they have been or may be addressed. In particular, we analyzed the importance of accurate mite identification, the difficulties faced in the evaluation of their host specificity, risk assessment of nontarget species, their impact on the weed, and the final steps of mite release and post-release monitoring.

Characterisation of Aceria massalongoi and a histopathological study of the leaf galls induced on chaste trees.

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.

Corrigendum: Chemical Ecology of Capnodis tenebrionis (L.) (Coleoptera: Buprestidae): Behavioral and Biochemical Strategies for Intraspecific and Host Interactions.

[This corrects the article DOI: 10.3389/fphys.2019.00604.].

Preventative Approach to Microbial Control of Capnodis tenebrionis by Soil Application of Metarhizium brunneum and Beauveria bassiana.

Management of the Mediterranean flat-headed root-borer, Capnodis tenebrionis, is critical due to the larvae's root localization. Neonate larvae can be exposed to natural enemies before penetrating the roots. Application of Metarhizium brunneum strain Mb7 and Beauveria bassiana strain GHA formulations on rice granules was investigated for their efficacy against C. tenebrionis larvae. Mb7 application, evaluated on apricot twigs, significantly and dose-dependently reduced colonization rates of neonates, with highest mortality at 108 conidia/g soil. Neonate susceptibility to Mb7 and GHA was evaluated on potted rootstocks (GF677 almond × peach, 2729 plum) planted in entomopathogenic fungi (EPF)-premixed soil (1.3-1.6 × 105 conidia/cm3 soil) or in EPF-free soil surface-treated with 5 g Mb7 fungal granules (1.25 × 109 conidia). Larval colonization rates were reduced 7.4-fold in 2729 by both fungi; only Mb7 completely prevented colonization of GF677 by larvae. Larvae inside plant galleries exhibited mycosis with EPF-treated soils and both fungi proliferated on larval frass. Mb7 conidia germinated in the rhizosphere of GF677, and conidia of both fungi remained viable throughout the trial. Galleria baiting technique was used on EPF-treated soil to evaluate EPF infectivity over time; Mb7 and GHA persisted 180 and 90 days post inoculation, respectively. The formulation (fungus-covered rice grains), delivery method (mixing with soil) and persistence (3-6 months) of Mb7 and GHA are feasible for potential field application to control C. tenebrionis.

Morphological and molecular characterization of the Colomerus vitis erineum strain (Trombidiformes: Eriophyidae) from grapevine erinea and buds.

The grapevine erineum mite strain (GEM) of Colomerus vitis (Pagenstecher) has spread throughout the main viticultural areas worldwide and was recently demonstrated to be a vector of Grapevine pinot gris virus (GPGV) and Grapevine inner necrosis virus (GINV). Its females mainly overwinter under the outer bud scales as winter morphs (deutogynes). Goals of this study were to characterize the morphology of protogynes (spring-summer morphs) and deutogynes (winter morphs), to confirm their genetic similarity, and to establish the seasonal period of the deutogyne occurrence. Buds or leaves from a single vineyard (cv. Luisa), Bari area, Apulia, Italy, infested with GEM were sampled 6 × from December 2015 to January 2017. Sixty-six traits commonly used for taxonomic identification were analysed on females. The length of the tibial setae l' on leg I and the tarsal setae ft' on leg II, as well as the number of smooth dorsal semiannuli differed significantly between protogynes and deutogynes, and were easier to detect than other significantly distinctive traits. ITS1 was investigated in individuals collected from buds and erinea, and the sequences confirmed that these two morphs have identical ITS1 fragments. The 1-year study demonstrated the simultaneous presence of protogynes and deutogynes in July and September 2016, whereas only protogynes were found in April and May 2016, and only deutogynes in December 2015 and January 2017.

Off-host survival of Eriophyoidea and remarks on their dispersal modes.

Dispersal of eriophyoid mites is crucial for the successful colonization of new plants. Literature suggests that their long-distance dispersal is through aerial transfer. During dispersal, eriophyoids might be captured in vapor or fine drops of water (perhaps most likely in clouds) where they might be protected against water loss and desiccation, but where they would have no food and be exposed to low temperatures and oxygen concentrations. Considerable resistance of these mites to these stressful environmental conditions is expected and has only partly been confirmed experimentally. The aim of the bioassays conducted here was to assess the survival of five eriophyoid species off their host plants, with poor oxygen availability under two temperature regimes. The bioassays were carried out on live mites dipped into two media used as microenvironments: (1) vaseline oil (used also as control treatment), and (2) water solution of Tween 80 (0.2%) and cycloheximide (50 mg/l). The bioassays were performed at 5 ± 1 and 25 ± 1 °C. The survival of mites was assessed weekly (5 °C) or daily (25 °C) by counting live and active specimens. The following species were subjected to the bioassays: Aceria caulobia (a stem gall mite), Aceria ficus (a vagrant mite), Cecidophyopsis hendersoni (a vagrant mite), Colomerus vitis (protogyne/male population and deutogyne morphs; a leaf gall mite) and Phytoptus avellanae (a bud gall mite). The survival rate of the mites was higher at 5 °C than at 25 °C under both experimental conditions. At 5 °C, the survival of almost all species was higher in the water solution (up to 6-7 weeks) than in vaseline oil (3-5 weeks). Longer survival was found for A. caulobia and P. avellanae (gall-making species) than for C. hendersoni and A. ficus (vagrant species). As expected, the deutogynes of C. vitis survived longer than its protogynes. The current results suggest that individuals of some of the tested species are well suited for withstanding cold, starvation and low oxygen rates, which could be found at higher atmospheric layers, within the clouds, allowing them an effective long-distance dispersal.

Correlations between As in Earthworms' Coelomic Fluid and As Bioavailability in Highly Polluted Soils as Revealed by Combined Laboratory X-ray Techniques.

Combined X-ray-based spectroscopy techniques were applied to investigate arsenic (As) bioaccumulation in earthworms (Eisenia andrei) exposed to six field-collected polluted soils (58-13 330 mg As kg-1). After 14 days of exposure to the arsenious soils, the As distribution in earthworms was examined by micro-X-ray fluorescence spectroscopy (µXRF), after epoxy resin embedding and preparing thin sections. Similar to µXRF data, XRF-computed tomography (XRF-CT) confirmed As accumulation in the coelom of intact earthworms. Therefore, total-reflection XRF was used to determine total As within both the whole earthworm's body (AsE) and coelomic fluid extracts (AsF). Bioaccumulation data (AsE and AsF) were thereafter evaluated in relation to total As concentration in soils (AsT) and to As mobile fraction in soils. A significant linear correlation (R2 = 0.97) was found between AsE and AsF, indicating that the As sequestrated into the coelomic fluid may reflect the total body concentration. Therefore, we may conclude that the As concentration in the coelomic fluid can be used as an index of As availability. This paper demonstrates that by combining different laboratory X-ray analytical techniques, compartmentalization and bioavailability of potentially toxic elements can be visualized and quantified within indicator-living organisms, thus contributing to an improved risk assessment for contaminated soils.

Chemical Ecology of Capnodis tenebrionis (L.) (Coleoptera: Buprestidae): Behavioral and Biochemical Strategies for Intraspecific and Host Interactions.

This study focuses on several aspects of communication strategies adopted by adults of the Mediterranean flat-headed root-borer Capnodis tenebrionis (Coleoptera: Buprestidae). Morphological studies on the structures involved in mate recognition and acceptance revealed the presence of porous areas in the pronota in both sexes. These areas were variable in shape and size, but proportionally larger in males. The presence of chaetic, basiconic, and coeloconic sensilla in the antennae of both males and females was verified. Bioassays revealed stereotyped rituals in males and the involvement of female pronotal secretions in mate recognition and acceptance. During the mating assays, the female's pronotum was covered by a biologically inert polymeric resin (DenFilTM), which prevented males from detecting the secretions and from completing the copulation ritual. The use of the resin allowed for the collection of chemical compounds. GC-MS analysis of the resin suggested it may be used to retain compounds from insect body surfaces and revealed sex-specific chemical profiles in the cuticles. Since adult C. tenebrionis may use volatile organic compounds (VOCs) emitted from leaves or shoots, the VOC emission profiles of apricot trees were characterized. Several volatiles related to plant-insect interactions involving fruit tree species of the Rosaceae family and buprestid beetles were identified. To improve understanding of how VOCs are perceived, candidate soluble olfactory proteins involved in chemoreception (odorant-binding proteins and chemosensory proteins) were identified using tissue and sex-specific RNA-seq data. The implications for chemical identification, physiological and ecological functions in intraspecific communication and insect-host interactions are discussed and potential applications for monitoring presented.

An Intimate Relationship Between Eriophyoid Mites and Their Host Plants - A Review.

Eriophyoid mites (Acari Eriophyoidea) are phytophagous arthropods forming intimate relationships with their host plants. These mites are associated with annual and perennial plants including ferns, and are highly specialized with a dominant monophagy. They can be classified in different ecological classes, i.e., vagrant, gall-making and refuge-seeking species. Many of them are major pests and some of them are vectors of plant pathogens. This paper critically reviews the knowledge on eriophyoids of agricultural importance with emphasis on sources for host plant resistance to these mites. The role of species belonging to the family Eriophyidae as vectors of plant viruses is discussed. Eriophyoid-host plant interactions, the susceptibility within selected crops and main host plant tolerance/resistance mechanisms are discussed. Fundamental concepts, subjects, and problems emerged in this review are pointed out and studies are suggested to clarify some controversial points.

Influence of the erineum strain of Colomerus vitis (Acari: Eriophyidae) on grape (Vitis vinifera) defense mechanisms.

Grape (Vitis vinifera) is commonly affected by the erineum strain of Colomerus vitis (GEM) in Iran and the susceptibility of grape cultivars to GEM is poorly understood. In order to evaluate the impact of GEM on grape and its defense mechanisms against the mite, an exploratory study was carried out on 19 cultivars (18 Iranian and the non-native Muscat Gordo). The differential susceptibility of cultivars to GEM was compared on the basis of the area of leaf damage induced by GEM. The cultivars White Thompson seedless of Bovanat, Atabaki Zarghan, Koladari Ghoochan and Sahebi Uroomie were less susceptible to GEM, whereas Ghalati Dodaj, Rishbaba, Muscat Gordo and Neyshaboori Birjand appeared to be the most affected by the mite. In a no-choice setup, plants of selected cultivars of these two groups were infested by GEM and assayed for 10 biomarkers usually related to plant stress mechanisms against plant feeders: the activity of defense enzymes-peroxidase (POX), polyphenol oxidase (PPO), superoxide dismutase (SOD), phenylalanine ammonia-lyase (PAL), catalase (CAT), the amount of total polyphenolics, total flavonoids, total soluble carbohydrates, hydrogen peroxide (H2O2), and malondialdehyde (MDA) expressing lipid peroxidation. The biomarkers were assessed in grape leaves 7 days before releasing the mites, as well as 7, 14 and 28 days after infestation (DAI). The activity of the enzymes and the amount of the compounds usually increased in percentage after mite infestation. A significant negative correlation was found between the area of leaf damage and PPO, POX, SOD, MDA and H2O2 for all sampling dates. The area of leaf damage showed a significant positive correlation with total soluble carbohydrates at 28 DAI, and significant negative correlations with CAT (at 14 and 28 DAI), PAL and total flavonoids (at 7 DAI). No correlation was observed between area of leaf damage and total polyphenolics. The biomarkers PPO, SOD, CAT activity and H2O2 provided the best explanation for the response of grape cultivars to GEM infestation.

Impact of the erineum strain of Colomerus vitis (Acari: Eriophyidae) on the development of plants of grapevine cultivars of Iran.

The present experiment was aimed at determining the influence of the grape erineum strain of Colomerus vitis (GEM) (Acari: Eriophyidae) on responses of local grapevine cultivars. GEM was applied at five density levels to each of five cultivars, i.e. Shahani, Sahebi Uroomie, Khalili Bovanat, Rishbaba and Sezdang Ghalat (listed from early to late grape ripening). The experiment was performed in a full factorial design (12 replicates each) and effects of the mite on the relative content of leaf chlorophyll, internode and cane length, leaf area and weight, number and size of the erinea, and percentage of leaves with erinea were investigated. Also mite density on leaves and in buds was assessed. Data were analyzed with a two-way ANOVA followed by Tukey's test to separate means among treatment levels and cultivars. The relative content of chlorophyll (expressed in Spad units) in infested leaves was reduced along with an increase in mite density and it was shown to be highly significant at the two higher mite density levels for Khalili Bovanat, Rishbaba and Sezdang Ghalat; Shahani and Sahebi Uroomie leaves appeared to be less affected by mite infestation. The highest mite density treatment displayed a strong correlation with weight (positive correlation) and size (negative correlation) of the leaves of four cultivars; leaves of Sahebi Uroomie appeared to be less affected. The reduced internode length was weak in infested plants. Most infested plants produced shorter canes and their lengths appeared to have a strong negative correlation with the highest mite density in four cultivars; canes of Sahebi Uroomie did not appear affected. At the highest mite density, canes of Khalili Bovanat and Sahebi Uroomie displayed the most and the least shortening effects, respectively. The percentage of leaves with erinea, as well as the number of erinea per leaves and the diameter of erinea increased along with the mite population density. The mite densities in buds (April 2014) and on leaves with erinea (in November 2013) were higher at the highest treatment level in the medium-late (Rishbaba) and late ripening (Sezdang Ghalat) cultivars, than in the early and early-medium ripening ones. Almost all data collected in the current experiment allowed the conclusion that Sahebi Uroomie and Shahani were less affected than the other cultivars (Khalili Bovanat, Rishbaba and Sezdang Ghalat).

External morphology of the mouthparts and observations on behavior of Tuckerella japonica on Camellia sinensis in the continental USA.

Tuckerella japonica Ehara (Acari: Tetranychoidea: Tuckerellidae) was found on stems of seedling plants of Camellia sinensis (L.) O. Kuntze (Theaceae) in the continental USA. This mite is able to pierce exposed green periderm tissue with its paired stylets on 1- to 3- or 4-year-old stems where the outer bark had split longitudinally. The mite was not found on branches older than 3 or 4 years, where splitting diminished and, eventually, a uniform covering of bark was formed. The mouthparts of T. japonica were examined under scanning electron microscopy and their external morphology was compared with known Tetranychoidea. There were usually one or two feeding holes in an area where the female subsequently deposited one or more eggs. Females were observed defending the areas where their eggs and/or young occurred. This behavior along with potentially limited access to exposed periderm or availability of shoots in the rows of plants may restrict higher populations of T. japonica from becoming established. The potential of T. japonica as an economic pest remains unknown at this time.

Transmission of grapevine Pinot gris virus by Colomerus vitis (Acari: Eriophyidae) to grapevine.

Grapevine Pinot gris virus (GPGV) is a new virus reported in Europe and several other grape-growing countries. In an attempt to identify a vector for GPGV, samples of the eriophyid mite Colomerus vitis collected from buds and erinea in GPGV-infected vines were analysed by RT-PCR, using specific primers. Molecular analysis revealed the presence of GPGV in C. vitis. Transmission trials were conducted using C. vitis collected from GPGV-infected vines. Mites were able to transmit GPGV to healthy grapevines, suggesting that C. vitis is a potential vector of this virus.

Eriophyoid mite fauna (Acari: Trombidiformes: Eriophyoidea) of Turkey: new species, new distribution reports and an updated catalogue.

More than one hundred species of Eriophyoidea have been recorded hitherto from Turkey. Within the last decade, a large plant survey was carried out in order to investigate the eriophyoid fauna present in Turkey, with particular emphasis on species affecting weeds and ornamental plants. In addition, the Turkish literature has been examined for previous records of eriophyoid mites. New species, Paraphytoptus intybi n. sp. on common cichory, Cichorium intybus (Compositae) and Phytoptus albae n. sp. on white poplar, Populus alba (Salicaceae), are described and illustrated herein. In addition, a further 31 species were found to be new records for the eriophyoid fauna of Turkey with Aceria calaceris, Phyllocoptes didelphis and Vasates immigrans being new reports for the Palaearctic region. All known eriophyoid species records from Turkey appearing in papers published up until March 2013 are listed in this catalogue along with remarks and information on their current distribution in Turkey and taxonomic status.

Eriophyoid mites (Acari: Trombidiformes: Eriophyoidea) of Rosales trees in Iran: two new species and three new records.

This paper describes two new species of Eriophyoidea associated with trees belonging to the order Rosales in the south-western portion of East Azerbaijan province, Iran, collected during a survey in 2011: Aceria lobolinguae n. sp. on Elaeagnus angustifolia L. (Elaeagnaceae) and Rhinophytoptus nemalobos n. sp. on Prunus domestica L. (Rosaceae). Additionally, Phyllocoptes abaenus Keifer on Prunus armeniaca L. (Rosaceae), Aculus fockeui (Nalepa & Trouessart) on Prunus amygdalus Stokes and Malus domestica Borkh. (Rosaceae), and Aceria mori (Keifer) on Morus alba L. (Moraceae) were collected and are new records for the mite fauna of Iran. New locality records and host plant data are provided for Eriophyes similis (Nalepa), Eriophyes pyri (Pagenstecher) and Calepitrimerus baileyi (Keifer) which are eriophyoid species previously known from Iran.