Patterns of parasitism by Amblyomma rotundatum (Ixodidae) on Rhinella schneideri (Bufonidae) in islands of São Francisco River, Minas Gerais, Brazil

Abstract: We sampled ticks from specimens of the rococo toad Rhinella schneideriby flannel dragging on two Islands located in the São Francisco River near the Três Marias hydroelectric dam, southeastern Brazil. A total of 120 toads was examined, of which 63 (52.5%) were parasitized only by Amblyomma rotundatumtotaling 96 larvae, 163 nymphs and 134 females. The burden of parasitism ranged from one to 43 ticks, with a mean intensity of infestation of 6.2±5.5 ticks per host. The tick A. rotundatumexhibited highly aggregated distribution. Peak abundance of larvae and nymphs occurred in the dry season (May to September), whereas peak abundance of females occurred in the wet season (October to April). We collected most ticks near the head and hind limbs of R. schneideri. The finding of two engorged A. rotundatumnymphs in the same resting places of two toads and the absence of this species in the dragged areas suggest a nidicolous behavior at the studied site.

Évaluation de suppléments alimentaires pour deux espèces d’acariens prédateurs, Amblyseius swirskii et Neoseiulus cucumeris (Acari: Phytoseiidae) pour l’optimisation du contrôle biologique du thrips des petits fruits (Frankliniella occidentalis) en serriculture

Projet réalisé en cotutelle avec Jacques Brodeur et Les Shipp

Reproductive performance of the generalist predator Hypoaspis aculeifer (Acari : Gamasida) when foraging on different invertebrate prey

In this study, we assessed the influence of prey quality and prey biomass during a standardized 3-week test on adult survival and reproductive output of the predatory mite Hypoaspis aculeifer when fed one of six different diets: springtails (Folsomia candida and Folsomia fimetaria), a storage mite (Caloglyphus cf. michaeli), an oligochaete (Enchytraeus crypticus), a nematode (Turbatrix silusiae), and a 1:1:1 mix of F. candida:F.fimetaria:E. crypticus. Our results revealed that a single prey species may be nutritionally sufficient for a 3-week period, as H. aculeifer performed equally well, or better, on a diet based on a 1:1:1 mix of F. candida:F. fimetaria:E. crypticus. However, when fed C. cf. michaeli, H. aculeifer had a poor reproductive output (< 200 juveniles) and a reduced survival (60-70%). Thus, investigators should validate their choice of prey prior to testing H. aculeifer performance during toxicant exposure. (c) 2007 Elsevier B.V. All rights reserved.

Eukaryotic ectosymbionts of Acari

The Acari is the most numerous and diverse group of the subphylum Chelicerata. With approximately 55 000 described species (and estimates of up to 1 million extant species), their adaptations for parasitism, phytophagy, mycophagy, saprophagy and predation rival other arthropods and challenge us with a wide variety of biological interactions. While a few studies have unravelled the nature of some endosymbiotic associations between mites or ticks and prokaryotes, almost nothing has been done yet regarding acarine eukaryotic ectosymbionts. Microbial ectosymbionts can benefit their hosts by providing nutrients, by aiding digestion, by enhancing communication, by assisting in mating and/or fertilization, by protecting their host against pathogenic microorganisms, against predation and so on. In this sketch, we introduce a number of described cases of fungal and protist ectosymbionts and discuss the role they might play in the life of their acarine hosts.

Occurrence of Poecilochirus austroasiaticus (Acari: Parasitidae) in forensic autopsies and its application on postmortem interval estimation

Despite the fact that mites were used at the dawn of forensic entomology to elucidate the postmortem interval, their use in current cases remains quite low for procedural reasons such as inadequate taxonomic knowledge. A special interest is focused on the phoretic stages of some mite species, because the phoront-host specificity allows us to deduce in many occasions the presence of the carrier (usually Diptera or Coleoptera) although it has not been seen in the sampling performed in situ or in the autopsy room. In this article, we describe two cases where Poecilochirus austroasiaticus Vitzthum (Acari: Parasitidae) was sampled in the autopsy room. In the first case, we could sample the host, Thanatophilus ruficornis (Küster) (Coleoptera: Silphidae), which was still carrying phoretic stages of the mite on the body. That attachment allowed, by observing starvation/feeding periods as a function of the digestive tract filling, the establishment of chronological cycles of phoretic behavior, showing maximum peaks of phoronts during arrival and departure from the corpse and the lowest values in the phase of host feeding. From the sarcosaprophagous fauna, we were able to determine in this case a minimum postmortem interval of 10 days. In the second case, we found no Silphidae at the place where the corpse was found or at the autopsy, but a postmortem interval of 13 days could be established by the high specificity of this interspecific relationship and the departure from the corpse of this family of Coleoptera.

Cardinium endosymbionts are widespread in synanthropic mite species(Acari: Astigmata)

‘Candidatus Cardinium’ is an intracellular endosymbiont or parasite frequently occurring in invertebrates including mites and ticks. In this work we report Cardinium bacteria in Astigmata mites and explore their incidence in synanthropic species. Amplification of a 776 bp bacterial 16S rRNA gene fragment, using specific primers, enabled identification of closely related Cardinium sequences in 13 laboratory-reared populations of mites. In addition, Cardinium sequences were identified in three wild mite populations. Large scale screening of these populations showed 100% prevalence of Cardinium, representing the highest incidence compared to other major Chelicerate groups.

Proctolaelaps euserratus, an ecologically unusual melicharid mite (Acari, Mesostigmata) associated with animal and human decomposition.

Proctolaelaps euserratus Karg, 1994 (Acari, Mesostigmata, Melicharidae), exclusivelly known from the Galápagos Islands till now, is newly reported from decaying matter of animal and human decomposition in various countries of Europe (Slovakia, Spain, United Kingdom). In consequence of high levels of necrophilia, the species is considered to be ecologically unusual among the other melicharids, which are primary associated with other than necrophilic habitats, such as galleries of subcorticolous beetles, bumble bee nests, flowers, etc. Proctolaelaps euserratus is reviewed, morphologically re-described (with first diagnostic characters for males), and considered as a new potential marker for later stages of decomposition, namely butyric fermentation and dry decomposition as classified in modern concepts of forensic acarology.

First contribution of mites (Acari) to the forensic analysis of hanged corpses: a case study from Spain

This case study from North Spain, highlights the importance of the collection of mites in addition to insects, from crime scenes or corpses subjected to environmental constraints that reduce or minimise insect activity, such as hanged corpses. In addition, this analysis highlights the relevance of arthropods’ collection in the field, even after the corpse has been moved away for autopsy. Four species of mites, phoretic on carrion (Silphidae) and rove (Staphylinidae) beetles, complemented and reinforced the autopsy analysis as well as the scarce information provided by insect activity. Poecilochirus carabi Canestrini & Canestrini, 1882 and Poecilochirus (Physoparasitus) davydovae Hyatt, 1980 (Mesostigmata: Parasitidae) were found in association with two Silphidae, Nicrophorus Fabricius, 1775 and Necrodes Leach, 1815, only when sampled in the autopsy room; this is suggestive of host-switching of mites and was likely due to the lack of availability of specific carriers in the field. The interpretation of the activity of Parasitidae mites both in the field and the autopsy room allows a better understanding of the timing and circumstances of decomposition. Phoretic deutonymphs of Pelzneria Scheucher 1957 (Astigmata: Histiostomatidae) were highly abundant, mostly P. crenulata Oudemans, 1909 and are reported for the first time on a Staphylinidae rove beetle, Creophilus maxillosus (L., 1758). Surprisingly, in this case study no Pelzneria were associated with the Silphidae found, which are their most common hosts, such as Necrodes littoralis (L., 1758) and Nicrophorus interruptus (Stephens, 1830). All histiostomatids were removed from the staphylinid (rove beetle) collected from the soil, at the scene of death, suggesting a recent arrival of the beetle. The occurrence of Staphylinidae beetles and their associated mites, such as Parasitidae and Pelzneria, and the information they provided would have been easily overlooked or lost if only the autopsy sampling would have been considered in the analysis of the case. The four mite species are reported for the first time for the Iberian Peninsula.

On spermiogenesis, sperm cell morphology and accompanying secretions of Copidognathus (Acari: Halacaridae)

The genus Copidognathus includes one-third of the species of Halacaridae described to date. This article describes spermiogenesis, sperm cell morphology and accompanying secretions from three species of Copidognathus. Initial spermatids have electron-dense cytoplasm with scattered mitochondria, a well-developed Golgi body, and nuclei with patches of heterochromatin. The cytoplasm and nuclei of these cells undergo intense swelling. The second spermatids are large electron-translucent cells, with small mitochondria in row along the remains of the endoplasmatic reticulum. In the succeeding stage, most of the cytoplasmatic structures and mitochondria have disappeared or have undergone profound transformations. Nuclei and cells elongate and chromatin begins to condense near the nuclear envelope. An acrosomal complex appears at the tip of the nucleus. The acrosomal filament is thick and runs the entire length of the nucleus. Plasmalemmal invaginations at the cell surface give rise to tubules filled with an electron-dense material. Sperm cell maturation is completed in the ventral portion of the germinal part, near the testicular lumen. As a final step in spermiogenesis, cytoplasm of the last spermatid undergoes a moderate condensation and the cariotheca disappears. Mature sperm cells were found in a matrix of ""simple"" and ""complex"" corpuscles, the latter consisting of flattened, spindle-shaped secreted bodies. Rather than in individual sperm aggregates, spermatozoa were contained in a single droplet inside the vas deferens, on a large secretion mass, structured as rows of platelets sunk in a fine grained matrix. Each mature sperm cell is covered by a thick secreted coat. In contrast to the genera Rhombognathus and other Actinotrichida, Copidognathus displays a set of features that must be regarded as apomorphic. The absence of usual mitochondria, the presence of electro-dense tubules and secretions similar to those present in Thalassarachna and Halacarellus, and the pattern of nuclear condensation are possibly shared apomorphies with these latter genera. (C) 2010 Elsevier GmbH. All rights reserved.

Cellular and molecular characterization of an embryonic cell line (BME26) from the tick Rhipicephalus (Boophilus) microplus

The cellular and molecular characteristics of a cell line (BME26) derived from embryos of the cattle tick Rhipicephalus (Boophilus) microplus were studied. The cells contained glycogen inclusions, numerous mitochondria, and vesicles with heterogeneous electron densities dispersed throughout the cytoplasm. Vesicles contained lipids and sequestered palladium meso-porphyrin (Pd-mP) and rhodamine-hemoglobin, suggesting their involvement in the autophagic and endocytic pathways. The cells phagocytosed yeast and expressed genes encoding the antimicrobial peptides (microplusin and defensin). A cDNA library was made and 898 unique mRNA sequences were obtained. Among them, 556 sequences were not significantly similar to any sequence found in public databases. Annotation using Gene Ontology revealed transcripts related to several different functional classes. We identified transcripts involved in immune response such as ferritin, serine proteases, protease inhibitors,. antimicrobial peptides, heat shock protein, glutathione S-transferase, peroxidase, and NADPH oxidase. BME26 cells transfected with a plasmid carrying a red fluorescent protein reporter gene (DsRed2) transiently expressed DsRed2 for up to 5 weeks. We conclude that BME26 can be used to experimentally analyze diverse biological processes that occur in R. (B.) microplus such as the innate immune response to tick-borne pathogens. (C) 2008 Elsevier Ltd. All rights reserved.

Some stigmaeid and eupalopsellid mites from citrus orchards in Brazil (Acari : Stigmaeidae and Eupalopsellidae)

Two new citrus-inhabiting species in the family Stigmaeidae, Agistemus brasiliensis n. sp. and Zetzellia malvinae n. sp., are described from citrus plants in São Paulo State, Brazil. Also, Agistemus floridanus Gonzalez is redescribed. Keys to genera of the Stigmaeidae and Eupalosellidae are provided along with a key to all species of these families associated with citrus.

Parâmetros biológicos e tabela de vida de Tetranychus urticae (Acari: Tetranychidae) em cultivares de mamão

Este trabalho foi realizado para avaliar o desenvolvimento e reprodução de Tetranychus urticae em cultivares comerciais de mamão Carica papaya. Foram utilizadas cultivares do grupo Formosa (Tainung 01 e Calimosa) e do grupo Solo (Golden e Sunrise). Para iniciar o bioensaio, foi transferida uma fêmea fertilizada por disco de folha (n=50 repetições) e retirado após um período de 12h, sendo avaliada a cada 12h, registrando-se o período de incubação, duração do estágio de imaturo, longevidade e fecundidade dos adultos e viabilidade desses estágios. Os resultados indicaram que as cultivares de mamão Tainung 01, Calimosa, Sunrise e Golden são bons hospedeiros para T. urticae. O parâmetro viabilidade não sofreu influência das cultivares em todas as fases de desenvolvimento avaliadas, apresentando valores superiores a 90%. Não houve diferença estatística entre as cultivares nos parâmetros: período de pre-oviposição e viabilidade dos ovos. A cultivar Tainung 01 apresentou menor potencial hospedeiro, embora houvesse menor duração nos estágios de ovo, larva, protoninfa e ovo-adulto. Nos parâmetros de tabela de vida e fertilidade, apresentou menores valores de Ro, r m e λ e maior valor de Td. Entre as cultivares, o Sunrise apresentou um elevado potencial hospedeiro para T. urticae, pois essa cultivar proporcionou a maior produção de ovos por fêmea, maior longevidade das fêmeas, bem como a maior taxa de reprodução (maior Ro, r m e λ e menor valor de Td).

Additional morphological characters and a new host for Aceria gymnoscuta Navia & Flechtmann (Acari, Eriophyidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A revision of the genus Pulaeus Den Heyer, with descriptions of a new genus and four new Brazilian species (Acari: Prostigmata: Cunaxidae)

A new genus, Lupaeus gen. nov., is created to contain part of the described species in the genus Pulaeus Den Heyer. A key to the genera of the tribe Pulaeini, to which these two genera belong, and one auxiliary key to the species of Brazil and South Africa, are provided. Four new species, viz. Pulaeus myrtaceus sp. nov., P. quadrisolenidius sp. nov., Lupaeus lectus sp. nov. and L. lobidorsalis sp. nov. are described and figured. P. martini Den Heyer, 1981 is designated as type species for the new genus. New nomenclatural combinations are reported.