A New Aculodes Species (Prostigmata: Eriophyidae) Described from an Invasive Weed by Morphological, Morphometric and DNA Barcode Analyses †

A new species of eriophyoid mite, Aculodes marcelli sp. nov., was discovered on cheatgrass, Anisantha tectorum (L.) Nevski (syn. Bromus tectorum L.), an annual grass that is native to Eurasia and Northern Africa. This grass was introduced to North America near the end of the 19th century and now is widespread and associated with the observed increases in the size, frequency, and intensity of wildfires in western N. America. In this paper, A. marcelli sp. nov., is morphologically described and illustrated. Compared with other Aculodes spp., it differs based on morphology and the sequence of the mitochondrial cytochrome oxidase gene, subunit I (MT-CO1). Results of morphometric analysis showed clear differentiation between A. marcelli sp. nov., and the most similar congener, A. altamurgiensis from Taeniatherum caput-medusae. Analysis of MT-CO1 sequence divergence revealed significant levels of genetic variation (17.7%) and supported the results from the morphometric analysis; therefore, it is determined that they are two different species. Aculodes marcelli sp. nov., is a new candidate agent for classical biological control of A. tectorum. © 2022 by the authors

Collection and detection of eriophyoid mites

Methods for collecting and detecting eriophyoid mites are crucial components in research, taxonomical and biological studies, and control programs for these organisms. Their small size, their specific host-plant interactions and their hidden life-style make them difficult to find in routine inspections. This review examines successful and unsuccessful approaches for collecting eriophyoid mites, and makes recommendations for their detection, supporting studies in taxonomy, ecology, biology, molecular systematics and population genetics

Eriophyid mites as biological control agents of two invasive alien plants in Europe: Ailanthus altissima and Ambrosia artemisiifolia.

Invasive alien plant species may have a strong impact on indigenous biodiversity and this is the case of Ailanthus altissima and Ambrosia artemisiifolia, whose control in the Euro-Mediterranean areas is required. Ailanthus altissima, commonly known as Tree of Heaven, is a fast-growing deciduous tree native of China, with is highly invasive. It is considered worldwide (Europe, Asia, South Africa, South-eastern Australia, North America) a serious invasive plant species of disturbed urban sites, competing with autochthonous flora and causing structural damages to railways, roads, buildings and historical monuments. In addition, it is also an important pest in rural areas, invading cropland, fencerows, forest edges and rocky areas. Ambrosia artemisiifolia, Common Ragweed, is an annual herbaceous plant, native of temperate North America regions, but considered invasive in Europe, parts of Asia and Australia. Its success as an invasive species is probably due to its ecological amplitude and its ability to colonise and dominate disturbed agricultural and anthropogenic habitats. The main impact is primarily due to the its abundant and highly allergenic pollen that induces health respiratory problems among human populations, but it is also an agricultural pest, competing with cultivated crops. Despite several attempts employing different control methods, it is clear that the total eradication of these alien species cannot be achieved and efforts have to be addressed for the ecological preservation of these ecosystems by the use biological and integrated control approaches. Conducting geographical surveys of the invasive species in question is the first step for potentially finding candidates to be used in the classical biological control of alien species. In particular, among the potential candidate agents associated with the target weed, eriophyid mites play a relevant role, because they are obligate plant feeders with high host specificity. For this reason, eriophyid mites have been considered potential control agents for both A. altissima and A. artemisiifolia. Very few eriophyid species have been recorded in association with the Tree of Heaven in its native areas. Recently, a new eriophyid species on A. altissima has been described in Hungary, pointing out the chance that a potential biocontrol agent of this invasive species is already present in the Palaeartic Region. This mite forms dense populations on the undersurface of the leaflets, which are responsible of making the lamina narrow, deformed, twisted, with edges folded or rolled downward toward the main vein of the leaflets. Drying and necrosis of the apical parts of the stems have been observed on heavily infested plants; whereas high infestations in young plants are also associated to the premature loss of leaves. An eriophyid mite species is already know to be associated with Common Ragweed in Europe and it seems to prevent male flower development and hence pollen production, but also result in a decrease in the number of viable seeds. First surveys regarding the distribution of these eriophyid mites associated with A. altissima and A. artemisiifolia, respectively, were carried out and will be presented in this communication, together with the first data regarding the potential impact of these mites on both invasive alien plant species

Anatomical Injury Induced by the Eriophyid Mite Aceria anthocoptes on the Leaves of Cirsium arvense

Anatomical injury of the leaves of the invasive species, Cirsium arvense (L.) Scop., caused by the eriophyid mite Aceria anthocoptes (Nal.), which is the only eriophyid mite that has been recorded on C. arvense worldwide, is described. The injury induced by the mite feeding on the leaves of C. arvense results in visible russeting and bronzing of the leaves. Other conspicuous deformations are folding and distortion of the leaf blade and curling of leaf edge, as well as gradual drying of leaves. The anatomical injury of the mature leaves of field-collected plants was limited to the epidermis of the lower leaf surface. However, on young leaves of experimentally infested plants, rust mite injuries extend to epidermal cells on both leaf surfaces and to those of deeper mesophyll layers. On these leaves, lesions on the lower leaf surface even affected the phloem of the vascular bundles. Leaf damage induced by A. anthocoptes is discussed with regard to the mite's potential as a biological control agent of C. arvense

Basal divergence of Eriophyoidea (Acariformes, Eupodina) inferred from combined partial COI and 28S gene sequences and CLSM genital anatomy

Eriophyoids are an ancient group of highly miniaturized, morphologically simplified and diverse phytoparasitic mites. Their possible numerous host-switch events have been accompanied by considerable homoplastic evolution. Although several morphological cladistic and molecular phylogenetic studies attempted to reconstruct phylogeny of Eriophyoidea, the major lineages of eriophyoids, as well as the evolutionary relationships between them, are still poorly understood. New phylogenetically informative data have been provided by the recent discovery of the early derivative pentasetacine genus Loboquintus, and observations on the eriophyoid reproductive anatomy. Herein, we use COI and D1-2 rRNA data of 73 eriophyoid species (including early derivative pentasetacines) from Europe, the Americas and South Africa to reconstruct part of the phylogeny of the superfamily, and infer on the basal divergence of eriophyoid taxa. In addition, a comparative CLSM study of the female internal genitalia was undertaken in order to find putative apomorphies, which can be used to improve the taxonomy of Eriophyoidea. The following molecular clades, marked by differences in genital anatomy and prodorsal shield setation, were found in our analyses: Loboquintus(Pentasetacus((Eriophyidae + Diptilomiopidae)(Phytoptidae-1, Phytoptidae-2))). The results of this study suggest that the superfamily Eriophyoidea comprises basal paraphyletic pentasetacines (Loboquintus and Pentasetacus), and two large monophyletic groups: Eriophyidae s.l. [containing paraphyletic Eriophyidae sensu Amrine et al. 2003 (=Eriophyidae s.str.) and Diptilomiopidae sensu Amrine et al. 2003] and Phytoptidae s.l. [containing monophyletic Phytoptidae sensu Boczek et al. 1989 (=Phytoptidae s.str.) and Nalepellidae sensu Boczek et al. 1989]. Putative morphological apomorphies (including genital and gnathosomal characters) supporting the clades revealed in molecular analyses are briefly discussed

Resistance of grapevine to the erineum strain of Colomerus vitis (Acari: Eriophyidae) in western Iran and its correlation with plant features.

Trisetacus juniperinus (Nalepa) sensu Keifer (Acari: Eriophyoidea: Phytoptidae) causes irregular development of buds, shoot deformations and stunted growth of trees, resulting in a serious threat to nurseries and young stands of Cupressus sempervirens L. (Mediterranean cypress). Recently, some cypress clones selected for their resistance to the fungal canker agent Seiridium cardinale (Wag.) have shown high susceptibility to the mite. Considering its tiny body, its hidden lifestyle inside the buds and the probable occurrence of other species (the vagrant Epitrimerus cupressi (Keifer) is common on the Mediterranean cypress in Italy), detection and monitoring of T. juniperinus require taxonomic expertise and are often time-consuming and challenging before serious damage is discernible. In the present study, a rapid, cost-effective PCR-based method was developed and validated to detect T. juniperinus on cypresses. The cytochrome c oxidase subunit I gene was amplified with degenerate and specific primers, but the latter were the only ones able to discriminate between T. juniperinus and E. cupressi. PCR products distinguished the two species both in a pool of individuals in a mixed population of both species and in single individuals, indicating the sensitivity of the detection method. PCR–RFLP (restriction fragment length polymorphism) by means of XmnI and XbaI endonucleases separated the two species. Furthermore, a washing-sieving protocol was used to make mite collection from the tree sample faster and simpler; this procedure did not interfere with the molecular detection of the species. The possibility of the routine use of this assay to monitor quarantine eriophyoids infesting plant material is discussed