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New phytoseiid mites from Mauritius Islands are being reported, including the description of two new species, Transeius pungi sp. nov. and Typhlodromus (Anthoseius) recurvitremus sp. nov., the description of the male of Phytoseius haroldi Ueckermann & Kreiter, and the redescriptions of two Amblyseius species only known from the type specimens, A. neoankaratrae Ueckermann & Loots and A. passiflorae Blommers. Furthermore, additional and complementary morphological information is provided for other eight species. This work brings the new total number of phytoseiid mites in Mauritius to seventeen species in nine genera.

The tomato spider mite Tetranychus evansi Baker and Pritchard (Acari: Tetranychidae), is a worldwide pest of solanaceous crops that has recently invaded many parts of the world. In the present study we examined the ecological impact of its arrival in the Mediterranean region. The spider mite and phytoseiid mite assemblages in various crop and non-crop plants in three areas of Valencia (Spain) were studied a few months before and 10 years after the invasion of T. evansi. According to rarefaction analyses, the invasion of T. evansi did not affect neither the total number of species in the mite community examined (spider mite and phytoseiid species) nor the number of species when the two communities were examined separately. However, after the invasion, the absolute and relative abundance of the native Tetranychus species was significantly reduced. Before the invasion, T. urticae and T. turkestani were the most abundant spider mites, accounting for 62.9 and 22.8 % of the specimens. After the invasion, T. evansi became the most abundant species, representing 60 % of the total spider mites recorded, whereas the abundance of T. urticae was significantly reduced (23 %). This reduction took place principally on non-crop plants, where native species were replaced by the invader. Null model analyses provided evidence for competition structuring the spider mite community on non-crop plants after the invasion of T. evansi. Resistance to acaricides, the absence of efficient native natural enemies, manipulation of the plant defenses and the web type produced by T. evansi are discussed as possible causes for the competitive displacement.

Predicting the potential geographical distribution of a species is particularly important for pests with strong invasive abilities. Tetranychus evansi Baker & Pritchard, possibly native to South America, is a spider mite pest of solanaceous crops. This mite is considered an invasive species in Africa and Europe. A CLIMEX model was developed to predict its global distribution. The model results fitted the known records of T. evansi except for some records in dry locations. Dryness as well as excess moisture stresses play important roles in limiting the spread of the mite in the tropics. In North America and Eurasia its potential distribution appears to be essentially limited by cold stress. Detailed potential distribution maps are provided for T. evansi in the Mediterranean Basin and in Japan. These two regions correspond to climatic borders for the species. Mite establishment in these areas can be explained by their relatively mild winters. The Mediterranean region is also the main area where tomato is grown in open fields in Europe and where the pest represents a threat. According to the model, the whole Mediterranean region has the potential to be extensively colonized by the mite. Wide expansion of the mite to new areas in Africa is also predicted. Agricultural issues highlighted by the modelled distribution of the pest are discussed.

Using a combination of the cytochrome oxidase subunit I gene (COI) and internal transcribed spacer (ITS) sequence information, cross-breeding, and morphological criteria, the taxonomic status of Tetranychus takafujii was reassessed. Described from Japan and very close to Tetranychus evansi, only the male empodium II separated the two species. Six T. evansi samples collected in Brazil, France, Kenya, Spain (including the Canary Islands), Taiwan, and two samples from Japan previously species-identified as T. takafujii, were examined. DNA sequences consistently divide the samples into two groups: group I held the mites from Brazil and France and group II contained the remaining samples of T. evansi together with the two mites collected in Japan. Likewise, crossbreeding experiments detected the same two groups that were reproductively partially incompatible. However, the Japanese samples were completely compatible with the rest of the group II T. evansi samples. The empodium II shape failed to distinguish consistently between the T. evansi and T. takafujii samples, but rather highlighted its variability, questioning its utility for separating these taxa. Congruent results support the co-specificity of the two taxa. It is concluded that T. takafuji is a junior synonym of T. evansi.

Eriophyoids have high potential as adventive mite species (AMS) because their small size make them difficult to detect, and can be easily distributed in world trade. Economic, social and environmental impact from adventive eriophyoid mites has been significant. Considerable attention has been given to adventive insect species while adventive mites have received little attention and little information is available for eriophyoids. This paper summarizes information on adventive eriophyoid mites, their impact, and the history of some important invasions. The status of adventive species of eriophyoids introduced as biological control agents of weeds is presented. A list of eriophyoid mites reported as invasive species worldwide is given. Pathways of concern and biosecurity actions to reduce the risk of eriophyoid mites are discussed. The need to raise public awareness of the risk and importance of these tiny organisms as AMS is emphasized. Scientific and technical challenges to deal with adventive eriophyoids are discussed.

Eriophyoids have high potential as adventive mite species (AMS) because their small size make them difficult to detect, and can be easily distributed in world trade. Economic, social and environmental impact from adventive eriophyoid mites has been significant. Considerable attention has been given to adventive insect species while adventive mites have received little attention and little information is available for eriophyoids. This paper summarizes information on adventive eriophyoid mites, their impact, and the history of some important invasions. The status of adventive species of eriophyoids introduced as biological control agents of weeds is presented. A list of eriophyoid mites reported as invasive species worldwide is given. Pathways of concern and biosecurity actions to reduce the risk of eriophyoid mites are discussed. The need to raise public awareness of the risk and importance of these tiny organisms as AMS is emphasized. Scientific and technical challenges to deal with adventive eriophyoids are discussed.