Biljana Vidović

Phenotypic variability in five Aceria spp. (Acari: Prostigmata: Eriophyoidea) inhabiting Cirsium species (Asteraceae) in Serbia

From about 250 Cirsium spp., only two Aceria spp. (Acari: Eriophyoidea) have been described, Aceria anthocoptes (Nal.) and Aceria cirsii Pet. B. & Shi. Host specificity, which generally characterizes eriophyoid mites, potentially leads to speciation, so we may expect more than two Aceria spp. and/or other infraspecific taxa. Furthermore, studies on host-related variability in the morphology of Aceria mites are generally lacking. The purpose of this study was to investigate quantitative morphological traits of five Aceria populations inhabiting five Cirsium spp. in Serbia. MANOVA analysis revealed significant differences in 23 commonly used morphological traits as well as four additional traits related to the prodorsal shield design. In addition, the most important qualitative traits using scanning electron microphotographs were studied in order to clarify phenotypic differences among five Aceria spp. Discriminant analysis identified eight traits that significantly differentiate five populations. UPGMA cluster analysis of the squared Mahalanobis distances indicates that A. cirsii was morphologically the most divergent, while A. anthocoptes populations from Cirsium arvense and Aceria sp. from Cirsium heterophyllum were isolated from the branch clustering Aceria spp. populations from Cirsium eriophorum and Cirsium creticum. Analysis of qualitative traits using SEM confirmed results obtained from the analysis of morphometric features.

Geometric morphometric study of geographic and host-related variability in Aceria spp. (Acari: Eriophyoidea) inhabiting Cirsium spp. (Asteraceae)

The russet mite, Aceria anthocoptes (Nalepa), is the only eriophyoid that has been recorded on Cirsium arvense (L.) Scop. It has been noted in several European countries and recently in the USA. In this study we explored the geographic and host-related variability of Aceria spp. inhabiting different Cirsium spp. We applied landmark-based geometric morphometric methods to study morphological variability of three body regions (ventral, coxigenital and prodorsal) of 13 Aceria spp. populations inhabiting five Cirsium spp. in Serbia (Europe) and four Cirsium spp. in Colorado (North America). Analyses of size and shape variation revealed statistically significant differences between Aceria spp. living on European native and North American native Cirsium spp., as well as between A. anthocoptes s.s. inhabiting European C. arvense and North American C. arvense. The coxigenital region was the most informative when considering inter-population shape differences. European Aceria spp. dwelling on Cirsium spp., including A. anthocoptes s.s. from C. arvense, are characterized by higher inter-population size and shape variability than their North American counterparts. This finding supports a Eurasian origin of A. anthocoptes, presumed to consist of a complex of cryptic taxa probably coevolved with host plants in the native environment. Morphological similarity among Aceria spp. inhabiting North American native Cirsium spp. may indicate that speciation of A. anthocoptes started relatively soon after the host shift to plants different from C. arvense in the invaded region.

The importance of cryptic species and subspecific populations in classic biological control of weeds: a North American perspective

Classical biological control of weeds depends on finding agents that are highly host-specific. This requires not only correctly understanding the identity of the target plant, sometimes to subspecific levels, in order to find suitable agents, but also identifying agents that are sufficiently specific to be safe and effective. Behavioral experiments and molecular genetic tools have revealed that some arthropod species previously thought to be polyphagous really consist of multiple cryptic species, host races or biotypes, some of which are more host-specific than others. Whereas true species are reproductively isolated, individuals from subspecific populations may potentially interbreed with those of other populations if they should encounter them. Furthermore, biotypes may consist of individuals sharing a genotype that is not fixed within a monophyletic group, and thus may not be evolutionarily stable. This raises the question of how such populations should be classified, and how to confirm the identity of live arthropods before releasing them as classical biological control agents. The existence of host races or cryptic species may greatly increase the number of prospective biological control agents available. However, it may also create new challenges for governmental regulation. These issues are discussed using pertinent examples, mainly from North America.

Phenetic and phylogenetic relationships among Aceria spp. (Acari: Eriophyoidea) inhabiting species within the family Brassicaceae in Serbia

We examined morphological and genetic differences among Aceria spp. inhabiting six Brassicaceae species in Serbia. Five of them have been already mentioned in the literature as original or alternate hosts of Aceria spp. (Berteroa incana (L.) DC., Capsella bursa-pastoris (L.) Medik., Cardamine hirsuta L., Lepidium draba L. and Sisymbrium orientale L.), whereas Aurinia petraea (Ard.) Schur was registered here for the first time as a host for Aceria sp. Results of morphometric analyses indicated clear differentiation of Aceria spp. from B. incana, L. draba, A. petraea and S. orientale, whereas the other two entities were less diverse and clustered together. Molecular analyses indicated that the average mean divergence over all sequence pairs was 18.3% (11.8–25.9%) and disclosed that the observed mtCOI distances between the six host-associated Aceria entities are large enough to represent differences between species. The Aceria sp. hosted by B. incana was morphologically and genetically most distinctive, whereas discrepancy between phenetic and phylogenetic relationships was found in the position of Aceria sp. hosted by L. draba when compared with those inhabiting C. hirsuta, S. orientale and C. bursa-pastoris.

A New Metaculus Species (Acari: Eriophyoidea) on Diplotaxis tenuifolia (Brassicaceae) From Serbia: A Combined Description Using Morphology and DNA Barcode Data

ABSTRACT A new species of eriophyoid mite, Metaculus diplotaxi n. sp. inhabiting Diplotaxis tenuifolia (L.) DC., is described from Serbia. To investigate interspecific variability between Metaculus spp. on three different Brassicaceae host plants (viz. D. tenuifolia, Lepidium latifolium (L.), Isatis tinctoria (L.)), we analyzed phenotypic variability of morphological traits and molecular sequences of the mitochondrial cytochrome oxidase subunit I (MT-CO1). Discriminant analysis identified seven traits that significantly differentiate three Metaculus spp: M. lepidifolii, M. rapistri, and M. diplotaxi n. sp. Analysis of MT-CO1 sequences supported the results obtained from the analysis of morphometric features.

Eriophyid mite Aceria artemisiifoliae sp.nov. (Acari: Eriophyoidea) potential biological control agent of invasive common ragweed, Ambrosia artemisiifolia L. (Asteraceae) in Serbia

Abstract Common ragweed, Ambrosia artemisiifolia L. (Asterales: Asteraceae), is an annual harmful weed of North American origin, now widely distributed in Central and Southern Europe, Asia and Australia. It is an agricultural weed, but it represents a serious risk for human health because its pollen can cause severe allergies. Recently, in the framework of the EU-COST Action ‘SMARTER’, an European program was started with the aim to develop sustainable management strategies for ragweed in Europe, with a special emphasis in the search and selection of biological control agents. Among them, the record of a new eriophyid mite Aceria species in Serbia has been considered as potential important biological control candidate. This paper describes the species following both morphological and bio-molecular approaches, and is giving some preliminary data on the geographical distribution and on the biology of the eriophyid mite on its host plant.

Comparative morphological analysis of apple blister mite, Eriophyes mali Nal., a new pest in Serbia.

SUMMARY The apple blister mite, Eriophyes mali Nalepa, 1926 (Acari: Prostigmata: Eriophyoidea), has been recently found in Serbia as a new pest of apple. The history of its research, the results of a morphological analysis and degree of infestation are presented. A comparison of the main morphological features of mites from different populations of remote geographical origin has shown that the apple blister mite from Serbia is most similar to another European population (Bulgarian [or Austrian?]) while it differs from E. mali originating from the USA and New Zealand. The percentage of infestation varied from 1.6% to 87.6%, with an average of 22.4%.

A new species and record of Aceria (Acari: Prostigmata: Eriophyoidea) on Carlina spp. (Asteraceae) from Serbia.

A new species of eriophyoid mite, Aceria utzkae n. sp., inhabiting Carlina acanthifolia subsp. utzka (Hacq.) Meusel & Kästner (Asteraceae) is described and illustrated. It is compared with Aceria carlinae (Nalepa), the only other species known to inhabit Carlina spp., and a differential diagnosis is provided. Both species are recorded from Serbia for the first time and a new host plant, Carlina vulgaris (Asteraceae) L., is also documented for Aceria carlinae.