Recent studies on Wolbachia-induced incompatibility in haplodiploid insects and mites have revealed a diversity of cytoplasmic incompatibility (CI) patterns among host species. Here, we report intraspecific diversity in CI expression among four strains of the arrhenotokous mite Tetranychus urticae and in T. turkestani. Variability of CI expression within T. urticae ranged from no CI to complete CI, and included either female embryonic mortality or male conversion types of CI. A fecundity cost attributed to the infection with the high-CI Wolbachia strain was the highest ever recorded for Wolbachia ()80 to )100% decrease). Sequence polymorphism at a 550-bp-portion of Wolbachia wsp gene revealed two clusters distant by 21%, one of which included three Wolbachia strains infecting mite populations sampled from the same host-plant species, but showing distinct CI patterns. These data are discussed in the light of theoretical predictions on the evolutionary pathways followed in this symbiotic interaction.

Status of two cryptic species, Typhlodromus exhilaratus Ragusa and Typhlodromus phialatus Athias-Henriot (Acari: Phytoseiidae): consequences for taxonomy -Zoologica Scripta, 35, 115-122. Typhlodromus phialatus and T. exhilaratus are morphologically close species. Their differentiation is based on the shape of the insemination apparatus and on idiosomal setae length. However, the setae length values are often intermediate between these two species and do not allow accurate identification. Furthermore, the handful of differences in insemination apparatus shape are also questionable as a means of differentiation. Synonymy between these species has thus been questioned. Three experiments were carried out. Idiosomal seta length measurements, molecular tests and cross experiments were conducted for three populations, identified as T. exhilaratus and T. phialatus according to the shape of their insemination apparatus. The results show that the variation range of seta lengths is great and that these criteria do not allow accurate separation of these populations into two species. However, molecular tests show a species-level nucleotide differentiation between them. Cross experiments confirm this result, showing complete reproduction incompatibility between the mites bearing different insemination apparatus shapes. Therefore, T. exhilaratus and T. phialatus could be considered to be two valid species and the insemination apparatus could be considered as a pertinent diagnostic criterion at the specific level.

The identity of specimens belonging to the genus Euseius Wainstein, 1962 found on several trees in France is investigated. These specimens are morphologically close to Euseius stipulatus (Athias-Henriot, 1960) except for the shape of the spermatheca and the dorsal shield reticulation. The aim of the present study was to determine if these specimens belong to this latter species and if the shape of the spermatheca could be considered a reliable diagnostic character. Thirty-four characters, including idiosomal seta lengths, were measured and molecular tests (12S rDNA, COI mtDNA) were carried out. Although small, significant differences between populations of Euseius sp. were observed. The morphometric differences between E. stipulatus and Euseius sp. were very small except for the seta z2 and for the length of the ventrianal shield, as well as the length and form of the spermatheca. Molecular analyses support that Euseius sp. and E. stipulatus are two different species. Euseius sp. has been described as a new species to science in another publication under the name Euseius gallicus . Reliability of some morphological characters for species diagnosis is discussed.

Morphological measurements and a mitochondrial molecular marker (COI) were used to identity specimens reported as Kampimodromus aberrans on hazelnut in the USA. Several species and populations of this genus were studied to assist with identification. Both data types showed that specimens from the USA differed from K. aberrans from other regions. USA specimens seem to belong to the same species as Kampimodromus specimens from France on hazelnut. These mites were morphologically similar to Kampimodromus coryli and K. corylosus, which according to the original descriptions, are distinguished by the presence or absence of a tooth on the movable digit of the chelicera, with K. coryli having one tooth and K. corylosus none. As chelicerae of Kampimodromus from hazelnut in the USA and France are toothless, they are assigned to the species K. corylosus. Studies showed that morphological characters traditionally used to identify Kampimodromus species, such as setal length, are of less value than other characters that are difficult to observe, such as the numbers of solenostomes and the presence of teeth on the movable digit of the chelicerae. Some synonyms are discussed.

Kampimodromus hmiminai McMurtry and Bounfour, 1989 and Kampimodromus adrianae Ferragut and Peña-Estévez, 2003 are two morphogically close species belonging to the family Phytoseiidae. They are the only two species within the genus Kampimodromus Nesbitt, 1951 that bear six solenostomes and a reduced ventrianal shield. Only some characters, such as the idiosomal seta lengths, idiosomal dorsal ornamentation, and setae ornamentation, distinguish them. Kampimodromus hmiminai has being reported from France and Morocco and K. adrianae from the Canary Islands. Our study tests the hypothesis of synonymy between these two species, using morphological measurements and molecular typing (mtDNA, cytochrome C oxidase I (COI)). The differences in idiosomal setae lengths between K. adrianae and K. hmiminai seem to be large enough to support their species status. However, genetic distances between these two species correspond to an intraspecific range of variation. According to the present data, K. adrianae and K. hmiminai could be considered synonyms, with morphologic differentiation as a result of geographic isolation. This result indicates that comparative setal length, seta serration, and dorsal shield ornementation should be used with caution for species differentiation within the genus Kampimodromus .

The identity of specimens belonging to the genus Euseius found on several trees in France is investigated. Previous molecular and morphological analyses have shown that the new species herein described is different from Euseius stipulatus. Among the 187 species belonging to the genus Euseius, four of them (Euseius querci, Euseius amissibilis, Euseius kirghisicus and Euseius longiverticalis) seem to be morphologically close to this new species. However, none were very similar. This paper reports the description of this new species: Euseius gallicus sp. nov. Kreiter and Tixier.

This study reports variation between populations of the phytoseiid mite Kampimodromus aberrans (Oudemans). The influence of seasons (summer and winter), different host plants, and localities on morphological variation was investigated to determine the reliability of the parameters usually used to distinguish species in the genus Kampimodromus. This study was conducted in southern France. The specimens examined consisted of three summer and three winter populations each collected from Celtis australis L., Quercus pubescens Willdenow (referred as Q. pubescens no. 1 in the text) and Corylus avellanae L., and three additional summer populations collected from each of Q. pubescens (referred as Q. pubescens no. 2 in the text), Vitis vinifera cv. Carignan and Vitis vinifera cv. Cabernet-Sauvignon. Significant differences were observed between the winter and summer populations. Females of summer populations had longer setae than females of winter populations. However, these differences are usually very small. Greatest differences were observed within the population collected in summer on Q. pubescens no. 1 from which two distinct groups of specimens were distinguished. To determine if more than one species of Kampimodromus were present on this plant, measurements of other closely related species were also included in the analysis. It was concluded that all the females studied belong to K. aberrans. However, the setal variations observed raised the following questions. (i) What is the validity of other closely related species whose setal lengths differ only slightly from those of K. aberrans? (ii) Are setal lengths useful characters to distinguish between closely related species in the genus Kampimodromus?

The abundance and diversity of phytoseiid mites were surveyed from April to September 2003 to 2005 in vineyards (Grenache and Syrah cultivars) co-planted with rows of Sorbus domestica or Pinus pinea and in monoculture plots of grapes in the South of France. Densities of phytoseiid mites were different on the two tree species, with P. pinea a more suitable host than S. domestica. Typhlodromus (Typhlodromus) exhilaratus was the dominant species occurring on grapes and on co-planted rows of S. domestica and P. pinea, whereas T. (T.) phialatus was the most abundant species in monoculture plots of both S. domestica and P. pinea. Factors determining the dominance of T. (T.) phialatus over T. (T.) exhilaratus in monoculture trees are discussed. In this study, agroforestry management did not affect phytoseiid diversity in vineyards, but did affect phytoseiid density, especially in 2005. The results obtained in 2003 and 2004 are not easy to discuss in this regard because of the low densities of mites observed during these 2 years (very dry climatic conditions and pesticide applications).