The morphology of juvenile stages of Crotonia pulcher (Beck, 1962) (Acari: Oribatida: Crotonioidea) with a redescription of the adult

The morphology of juvenile and adult stages of the Neotropical oribatid mite Crotonia pulcher (Beck, 1962) from Ecuador is described and illustrated. This species seems to be a member of the cophinaria group of Crotonia.     

洼甲螨科的分类研究进展(蜱螨亚纲:甲螨目:懒甲螨总科)

洼甲螨科隶属于蜱螨亚纲甲螨目懒甲螨总科,是低等甲螨中进化相对较高级,介于低等甲螨和高等甲螨之间的过渡类群,广泛分布于世界各大动物地理区,目前全世界有3属5亚属79种5亚种,国内现知2属16种.综述了洼甲螨科该科的分类沿革及分类研究进展;概述了洼甲螨科各属(亚属)的地理分布,指出该科目前所知分布较多的是古北界、新北界、东洋界;对中国洼甲螨科已知种进行了区系总结,目前青藏区和蒙新区各仅知1种,主要原因是缺乏深入研究;编制了洼甲螨科3个属及5个亚属和中国已知2属16种的分类检索表.     

Ontogenetic changes in the chemistry and morphology of oil glands in Hermannia convexa (Acari: Oribatida)

As a first example for the chemistry of oil gland secretions in the Hermannioidea (one of the three superfamilies of desmonomatan Oribatida), the oil gland secretion of Hermannia convexa was investigated by gas chromatography–mass spectrometry. Hexane extracts of all juvenile stages showed a multicomponent chromatographic pattern, mainly consisting of well-known oil gland secretion components such as neral, geranial, -acaridial and the unsaturated C17-hydrocarbons, 6,9-heptadecadiene and 8-heptadecene. The secretion profiles of juveniles varied slightly between samples of two different collections, namely in the presence of -acaridial and 8-heptadecene. Furthermore, a minor component, identified as 1,8-cineole (= eucalyptol) and hitherto not known from oil gland secretions of other species, was recorded in both juvenile and adult extracts. In adult profiles, 1,8-cineole, in low amounts, represented the only detectable component; thus, their profiles fundamentally differed from those of juveniles. A subsequent histological investigation revealed well developed oil glands in all juvenile stages, but degenerated oil glands in adults, consistent with the chemical data. So far, apart from H. convexa, degeneration of oil glands in the course of ontogenetic development is only known from a brachypylid species; on the other hand, chemical oil gland-polymorphism between juveniles and adults may occur in closely related Nothridae while it does not occur in oil glands of early- and middle-derivative Oribatida (Parhyposomata, Mixonomata, trhypochthoniid Desmonomata), nor in astigmatid mites.This revised version was published online in May 2005 with a corrected cover date.     

Two new species of oribatid mites of the family Galumnidae (Acari,Oribatida) from Vietnam

Two new species of oribatid mites of the family Galumnidae, Allogalumna monodactyla sp. n. and Galumna (Galumna) paracalcicola sp. n., are described from dark loamy soil under crown of Ficus sp. in southern Vietnam. Allogalumna monodactyla sp. n. is the first identified member of Allogalumna recorded for Vietnam. The identification keys to the species of Allogalumna from the Oriental region and species of Galumna (Galumna) from Vietnam and the calcicola-group are given.     

Chemistry of the oil gland secretion of Collohmannia gigantea (Acari: Oribatida)

The chemistry of the lemon-scented oil gland secretion ofCollohmannia gigantea, a middle-derivative mixonomatanoribatid mite, was investigated by gas chromatography – massspectrometry.Gas chromatographic profiles of whole body extracts of C.gigantea revealed two distinct chromatographic zones, the firstcontaining a set of six volatile compounds, comprising the lemon-scentedmonoterpene aldehydes neral and geranial, the scented monoterpene ester nerylformate, a distinctly scented aromatic aldehyde(2-hydroxy-6-methyl-benzaldehyde= 2,6-HMBD), and the two non-scented hydrocarbons, tridecane and pentadecane.All six components appeared to be present in steady relative proportions inscenting mites only, indicating their unity within the scented secretion. Incontrast, the components of the second chromatographic zone were less volatileand found in both, scenting and non-scenting mites. Chemically, they representaset of fatty acids of already known cuticular origin.The secretion bouquet ofthe first chromatographic zone was linked with oil glands by histochemicalmeans: large amounts of aldehydes were present only in oil gland reservoirs,notin any other region of the mite body. While chemical profiles of oil glandsecretions of several dozen astigmatid mites are known, only one other oribatidoil gland composition, from a desmonomatan species, has been elucidated, beingalmost the same as that of C. gigantea. Moreover, allcomponents of these two secretions are widely distributed amongst astigmatidmite species and may also be common in a restricted set of middle-derivativeoribatids. These findings are consistent with the idea of astigmatid miteoriginfrom a mixonomatan-desmonomatan group.     

Molecular phylogeny of oribatid mites (Oribatida, Acari): evidence for multiple radiations of parthenogenetic lineages

Nucleotide sequences of the D3 expansion segment and its flanking regions of the 28S rDNA gene were used to evaluate phylogenetic relationships among representative sexual and asexual oribatid mites (Oribatida, Acariformes). The aim of this study was to investigate the hypothesis that oribatid mites consist of species-rich clusters of asexual species that may have radiated while being parthenogenetic. Furthermore, the systematic position of the astigmate mites (Astigmata, Acariformes) which have been hypothesised to represent a paedomorphic lineage within the oribatid mites, is investigated. This is the first phylogenetic tree for oribatid mites s.l. (incl. Astigmata) based on nucleotide sequences. Intraspecific genetic variation in the D3 region was very low, confirming the hypothesis that this region is a good species marker. Results from neighbour joining (NJ) and maximum parsimony (MP) algorithms indicate that several species-rich parthenogenetic groups like Camisiidae, Nanhermanniidae and Malaconothridae are monophyletic, consistent with the hypothesis that some oribatid mite groups diversified despite being parthenogenetic. The MP and maximum likelihood (ML) method indicated that the D3 region is a good tool for elucidating the relationship of oribatid mite species on a small scale(genera, families) but is not reliable for large-scale taxonomy, because branches from the NJ algorithm collapsed in the MP and ML tree. In all trees calculated by different algorithms the Astigmata clustered within the oribatid mites, as proposed earlier.     

The genus Galumna in Nepalese oribatid mite fauna,with notes on systematic placement of some species (Acari,Oribatida, Galumnidae)

The oribatid mite genus Galumna (Oribatida, Galumnidae) is recorded for the first time in Nepal. A new species, Galumna tetraporosasp. n., is described from soil of secondary mixed broadleaved forest. It is most similar morphologically to G. tokyoensis Aoki, 1966 and G. valida Aoki, 1994, however, it differs from both by the absence of interlamellar setae and the presence of two pairs of notogastral porose areas Aa. Galumna granalata Aoki, 1984 is redescribed on the basis of specimens from Nepal. Galumna floridae (Jacot, 1929) and G. hexagona Balogh, 1960 are transferred to the genus Notogalumna; G. mauritii Mahunka, 1978 is transferred to the genus Dimidiogalumna.     

The camerobiid mites (Acari, Camerobiidae) of Turkey

Three new species of Neophyllobius viz. N. demirsoyi, N. yunusi, N. bolvadinensis and male, protonymph and larvae of N. lachishensis Bolland, 1998 from Turkey are described and illustrated. Neophyllobius lachishensis is reported from Turkey for the first time.     

The morphology of the larval stages of three species (Arrenurus mediorotundatus Thor, 1898; Arrenurus conicus Piers 1894; and Arrenurus cylindratus Piers, 1896) of the Megaluracarus subgenus (Acari: Hydrachnidia: Arrenuridae)

The morphology of the larval stages of three species (Arrenurus mediorotundatus, Arrenurus conicus and Arrenurus cylindratus) belonging to the Megaluracarus subgenus is described. Particular attention is paid to the common characters of the three species in which they differ from the other species belonging to the other subgenera. These are: the shape of the excretory pore plate, the shape of the dorsal plate, the length of coxal plate II medial margin and the C1-CpI, C4-CpIII distances. Other characters differ between the three species also. These are: the shape of the dorsal plate, the shape of coxal plate III, the shape of excretory pore plate and the presence or absence of secondary setae of the IFe3 setae.     

Hypocrella panamensis sp. nov. (Clavicipitaceae, Hypocreales): a new species infecting scale insects on Piper carrilloanum in Panama

A new species, Hypocrella panamensis, is described from collections and cultures obtained on Barro Colorado Island, Panama. In order to aid in placement of this fungus, phylogenetic analyses were conducted using LSU (rDNA) sequences. Hypocrella panamensis is characterized by possessing pulvinate stromata with a Lecanicillium-like anamorphic state and superficial perithecia. Hypocrella panamensis consistently grouped in a clade containing Hypocrella nectrioides, H. phyllogena, and H. africana (100 % PP). Most species of Hypocrella possess Aschersonia or Hirsutella anamorphs. Hypocrella panamensis is unique in the genus Hypocrella in possession of a Lecanicillium-like anamorphic state. In its biological habit Hypocrella panamensis is similar to other species in Hypocrella in that it infects and degrades the scale insect, then grows superficially on nutrients that emerge to the plant surface through the stylet wound.     

Rediscovery and redescription of the marine peritrichous ciliate Epicarchesium abrae (Precht, 1935) nov. comb. (Protozoa, Ciliophora, Peritrichia)

The morphology, infraciliature and silverline system of the marine peritrichous ciliate, Epicarchesium abrae (Precht, 1935) nov. comb., isolated from an abalone-farming pond off the coast of Qingdao, China, are investigated. E. abrae is characterized by: size of zooid in vivo 68 μm×48 μm on average; macronucleus usually J-shaped; one dorsally-located contractile-vacuole; colony regularly dichotomously branched with 4–16 zooids; total number of transverse silverlines 62–72, from peristome to aboral ciliary wreath 41–47, from aboral ciliary wreath to scopula 21–25; outer kinety of peniculus 3 prolonged and converges with peniculus 1.     

Microbial diversity in the predatory mite Metaseiulus occidentalis (Acari: Phytoseiidae) and its prey, Tetranychus urticae (Acari: Tetranychidae)

Microorganisms associated with the predatory mite Metaseiulus (=Typhlodromus or Galendromus) occidentalis (Nesbitt) and its prey, the two-spotted spider mite Tetranychus urticae (Koch), were assessed using a high-fidelity polymerase chain reaction (PCR) protocol and primers designed to identify Eubacteria, Archaeabacteria, iridoviruses, Helicosporidia, Cytophaga-like microorganisms, Wolbachia and its bacteriophage WO, fungi and yeast-like organisms. Sequences from four bacterial species related to Wolbachia (α-Proteobacteria), Cardinium, Bacteroidetes, and Enterobacter (γ-Proteobacteria) were obtained from M. occidentalis, and three sequences related to Wolbachia, Rickettsia, and Caulobacter (α-Proteobacteria) were obtained from T. urticae. No nucleotide differences were detected between the 16S rRNA, wspA or wspB Wolbachia sequences obtained from M. occidentalis and T. urticae, which suggest that horizontal transfer of Wolbachia could have occurred. Southern blot analyses of genomic DNA from both M. occidentalis and T. urticae using wspA probes were negative, indicating that this Wolbachia sequence is not integrated into the nuclear genome of either species. Two of the T. urticae colonies tested contained the WO bacteriophage, but none of the six M. occidentalis populations were infected. New M. occidentalis-specific forward and reverse 16S rRNA primers based on the Wolbachia, Cardinium, Bacteroidetes, and Enterobacter sequences obtained were designed and used to amplify PCR products from each of two laboratory and four field-collected samples of M. occidentalis females and eggs, indicating that these infections are widespread. Likewise, species-specific primers for T. urticae were designed for the Wolbachia, Rickettsia, and Caulobacter sequences obtained and used to evaluate T. urticae from strawberries, wine grapes, hops, almonds, and cherries from California, Washington, and Florida; all were positive for Wolbachia and Caulobacter but two of the six were negative for Rickettsia. None of the M. occidentalis colonies tested were positive for the microsporidium Oligosporidium occidentalis, which previously had been associated with a pathogenic condition in some of our laboratory colonies. The Gainesville colonies of M. occidentalis and T. urticae were negative for iridovirus, Archaeabacteria, fungi, Helicosporidia, and yeast-like organisms. So far, Wolbachia is the only symbiont that is shared by this predator and its prey.     

The Mechanism of Oviposition in Argas (Persicargas) Walkerae (Acari: Argasidae)

The process of oviposition in A. walkerae was observed and found to be a sequence of exactly coordinated, interlocking events independent of the age of ticks. Egg-laying always commenced with numerous dorso-ventral movements of the capitulum. The pedipalps were spread during the last dorso-ventral movement and lowered to the ventral body wall embracing the genital aperture on both sides. Simultaneously, the cuticular sac of Gene's organ emerged and immediately everted maximally. Immediately afterwards the vestibulum vaginae prolapsed from the genital aperture touching the cuticular sac. The vestibulum vaginae handed over an egg to the cuticular sac after a brief contact. Then the vestibulum vaginae invaginated, the pedipalps closed and the cuticular sac was retracted. Finally, the capitulum very frequently moved up and down and the free egg was pushed in front of the ticks. The total time of laying an egg averaged 27min in both 4-week-old and 12-month-old ticks. In 4-week and 12-month-old ticks, egg-laying was preceded by a mean preoviposition period of 6.1 days and 7.5 days, respectively, while the mean oviposition was completed in 14 and 10 days and the average egg totals were 119 and 103.     

Delimiting species boundaries within Dermanyssus Dugès, 1834 (Acari:Dermanyssidae) using a total evidence approach

The genus Dermanyssus is currently composed of 24 hematophagous mite species and includes the Poultry Red Mite, Dermanyssus gallinae, a serious pest in poultry houses. Morphologically, Dermanyssus species fall into two groups corresponding to Moss’ gallinae-group and to hirsutus-group + Microdermanyssus. Species of the gallinae-group exhibit high levels of morphological variability, and are nearly impossible to distinguish. Species of the second group display consistent characters and host associations and are easily distinguishable. Species of the gallinae-group tend to be the major problems in poultry houses and it is unknown whether D. gallinae is the only pest, or if there are numerous cryptic species present in the system.Twenty species of Dermanyssus were tested phylogenetically based on 46 morphological characters. A subset of species, mainly of the gallinae-group, represented each by several populations, was sequenced for two mitochondrial and one nuclear gene regions. This allowed testing their specific status and their interrelationships based and on morphological and molecular characters. The molecular data was analysed separately and in combination with morphological characters. As expected, morphology did a poor job resolving relationships.Molecular data proved more informative. The resulting phylogenetic hypotheses brought some information about interrelationships among species of the gallinae-group showing a split into two main clades. The invasion of human managed environments seems to occur only in taxa within one of the two clades. The host spectrum seems to get enlarged in more derived taxa in the same clade. A delineation of six species within the gallinae-group is provided. Additionally, a key for morphological identification of these species is provided. D. gallinae appears to be the only pest in poultry houses, but is composed of several different and more or less strongly isolated lineages. A new species found from the black swift is described.     

Interactions of two natural enemies of Tetranychus evansi, the fungal pathogen Neozygites floridana (Zygomycetes: Entomophthorales) and the predatory mite, Phytoseiulus longipes (Acari: Phytoseiidae)

Tetranychus evansi is an exotic pest of Solanaceous crops in Africa discovered in Zimbabwe in 1979. Two natural enemies, the predatory mite Phytoseiulus longipes and the fungal pathogen Neozygites floridana are important causes of mortality in T. evansi populations in Brazil. The first part of this study assessed the effects of N. floridana on predation and oviposition of P. longipes fed on N. floridana infected T. evansi and T. urticae. No N. floridana hyphal bodies were found in P. longipes after this feeding, demonstrating that N. floridana is not pathogenic to P. longipes and does not affect its oviposition. The second part of the study investigated the time spent on searching for and consuming of eggs on leaf discs with and without N. floridana capilliconidia. Both the searching and the feeding time on the first egg were similar on leaf discs with and without capilliconidia. When P. longipes was offered the choice of feeding on eggs on leaf discs with or without capilliconidia, the numbers of eggs consumed were not different. The only N. floridana effect observed on P. longipes was reduced egg predation. In addition, increased time spent grooming on leaf discs with capilliconidia was observed. P. longipes was efficient in removing most capilliconidia attached to the body through self-grooming behavior. This suggests that although the predator did not avoid areas with capilliconidia, it detected and removed most capilliconidia attached to the body. Increased grooming may account for the lower egg predation rates.