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At least 199 records · Page 11Linked to original sources
PubMed2005

First detection of Anaplasma phagocytophilum in quill mites (Acari: Syringophilidae) parasitizing passerine birds.

Forest passerine birds and their ectoparasites: Ixodes ricinus ticks and Syringophilidae quill mites were surveyed for infection with Anaplasma phagocytophilum in west-central Poland. Of 126 birds captured from May to June of 2002, 71 (56.3%) comprising eight species, hosted immature I. ricinus ticks. A total of 383 ticks and 71 blood samples collected from tick-infested birds were investigated by PCR. The pathogen was not detected in either bird-derived ticks or in blood samples. Among the captured birds, a total of 14 individuals representing four species hosted quill mites from the family Syringophilidae. Three of the 14 mite pools recovered from the 14 mite-infested birds harbored A. phagocytophilum DNA by amplifying both the epank1 and p44 gene. The PCR-positive pools originated from one blackbird and two starlings. The specific biology of syringophilid mites, which parasitize exclusively inside the quill of feathers, feeding on host subcutaneous fluids, implies that they must have acquired the pathogen from a bacteremic bird. These results provide the first indirect evidence that at least some passerine hosts are prone to develop systemic infection with A. phagocytophilum under natural conditions. Consequently, the infected quill mites may serve as a "biological marker" of past or current infection with the agent within birds.

Acari↗
PubMed1999

[Allergy to squid and acari in a child].

UNLABELLED: Anaphylactic reactions after consumption of squid by patients sensitized to house dust mites have been reported several times. CASE REPORT: A child allergic to dust mites developed an angioneurotic edema after eating squid. An immunoallergological assessment, including the prick test, labial test and IgE RAST revealed an allergy associated to both dust mites and squid. CONCLUSIONS: In light of the potential seriousness of anaphylactic reactions, parents of children allergic to dust mites and these children should be made aware of the increased risk of allergies to squid that they may face.

Acari↗
PubMed2004

Acaricidal activity of constituents identified in Foeniculum vulgare fruit oil against Dermatophagoides spp. (Acari: Pyroglyphidae).

Acaricidal activities of components derived from Foeniculum vulgare fruit oil against Dermatophagoides farinae and Dermatophagoides pteronyssinus were examined using direct contact application and compared with that of the commercial repellent benzyl benzoate. The major biologically active constituent of Foeniculum fruit oil was characterized as (+)-fenchone by spectroscopic analyses. On the basis of LD(50) values, the compound most toxic to D. farinae was p-anisaldehyde (11.3 mg/m(2)) followed by (+)-fenchone (38.9 mg/m(2)), (-)-fenchone (41.8 mg/m(2)), benzyl benzoate (89.2 mg/m(2)), thymol (90.3 mg/m(2)), and estragol (413.3 mg/m(2)). Against D. pteronyssinus, p-anisaldehyde (10.1 mg/m(2)) was much more effective than benzyl benzoate (67.5 mg/m(2)), thymol (68.5 mg/m(2)), and estragol (389.9 mg/m(2)). These results indicate that the acaricidal activity of F. vulgare fruit oil likely results from (+)-fenchone and p-anisaldehyde. (+)-Fenchone was 20.3 times more abundant in the oil than p-anisaldehyde. (+)-Fenchone and p-anisaldehyde merit further study as potential house dust mite control agents or as lead compounds.

Acari↗
PubMed1999

Genetic differentiation of mites of the genus Chorioptes (Acari: Psoroptidae).

In an effort to clarify the species status of mites of the genus Chorioptes the second internal transcribed spacer of the rRNA gene was characterized in 14 isolates from cattle, horse, sheep and llama of different geographic origins. The genotypes segregated into two clearly separated groups of DNA sequences. In addition, two phenotypes could be distinguished by the lengths of the outer opisthosomal setae of male adults which had previously been designated as Chorioptes bovis and Chorioptes texanus. The bipartite division of genotypes and phenotypes correlated completely in all isolates. Nine out of ten cattle isolates from three continents were determined to be C. texanus including the first description in Europe and Northern America. Chorioptes texanus appears to have a wider geographic distribution than previously known. Chorioptes bovis was found in four different host species. The apparent lack of host specificity of both species implicates a potential that mites are dispersed freely in a wide range of hosts and this might have contributed to the wide geographic distribution of these species.

Acari↗
PubMed1999

The behavioral responses by larvae of the water mite Unionicola foili (Acari: Unionicolidae) to gravity, light and host chemicals: adaptations for transmission success?

The life cycle of the water mite Unionicola foili includes larvae that parasitize chironomid dipterans, and nymphs and adults that occur in association with the freshwater mussel Utterbackia imbecillis. The georesponses and photoresponses of larval U. foili in the presence of chemical substances from chironomids and mussels both prior to (= pre-chironomid larvae) and after their parasitism with chironomids (= post-chironomid larvae) were examined in the laboratory. The responses of larval U. foili to light and gravity changed during larval ontogeny and varied depending on the chemistry of the medium in which they were examined. Pre-chironomid larvae preferentially responded to water modified by chironomids given that negative phototaxis and positive georesponses were elicited only in the presence of water that had been modified by these hosts. Post-chironomid larvae exhibited host-induced negative phototaxis only in the presence of mussel-modified water. Post-chironomid larvae were consistently geopositive when exposed to water modified by mussels or chironomids. The pattern of responses exhibited by larval U. foili to light and gravity are interpreted as adaptations for locating potential hosts in the field.

Acari↗
PubMed2003

Three new species of larval Charletonia Oudemans, 1910 (Acari: Prostigmata: Erythraeidae) and the first record of Charletonia krendowskyi (Feider, 1954) from Rhodes, Greece.

Three new species of larval Charletonia Oudemans, 1910 from Rhodes, Greece are described: C. dalegori from an undetermined orthopteran, C. glifadaensis from Oedipoda sp. (Orthoptera: Acrididae: Oedipodinae) and C. kaliksti from Aiolopus sp. (Orthoptera: Acrididae: Oedipodinae). C. krendowskyi is recorded for the first time from Greece. A key to the European species of larval Charletonia is provided.

Acari↗
PubMed2003

The effect of temperature on the functional response of Phytoseiulus persimilis (Acari: Phytoseiidae).

Environmental variables, such as temperature, are important in determining the efficiency of biological control in ornamental crops. This paper examines the effect of temperature on the functional response of adult female Phytoseiulus persimilis to eggs of the spider mite, Tetranychus urticae. The functional response was determined using a new functional response assay technique with plant stems as an arena, rather than leaf discs. The use of plant stems allows the influence that plant structure has on predation to be incorporated into the assay. Control assays were also used (without predators) to estimate natural losses of prey. The data were analysed using a binomial model, with the use of Abbot's formula to correct for the losses in the controls. A combined equation to describe the effect of temperature and prey density on the predation rate of Phytoseiulus persimilis was derived. The results showed that more prey are eaten as the temperature increases from 15 degrees C to 25 degrees C, but the number of prey eaten then declines at 30 degrees C, although not to the levels seen at 20 degrees C. The implication of these results for biological control in ornamental crops, where the temperature can often exceed 30 degrees C, is discussed.

Acari↗
PubMed2003

Diapause and implications for control of Penthaleus species and Halotydeus destructor (Acari: Penthaleidae) in southeastern Australia.

Blue oat mites, Penthaleus spp., and redlegged earth mites, Halotydeus destructor (Tucker) are major winter pests of a variety of crops and pastures. In southern Australia earth mites exhibit a facultative egg diapause to survive unfavorable summer conditions. The initiation of diapause egg production in earth mites was investigated using field and shade-house experiments. Species differed in their timing of diapause. H. destructor mainly produced diapausing eggs towards the end of the active mite season in spring, although small numbers were also produced in winter. In contrast, Penthaleus major (Dugés) produced diapause eggs almost immediately after emergence in autumn and continued producing these eggs throughout the season. Penthaleus falcatus (Qin and Halliday) also produced diapause eggs in early winter, although the first appearance of these eggs was slightly later in the season than for P. major. The diapause response of an undescribed species was also somewhat later than in P. major and P. falcatus, but earlier than in H. destructor. Electrophoresis of P. major samples indicated that clones of this parthenogenic species may differ in their timing of diapause egg production, providing another potential selective factor contributing to the maintenance of clonal diversity within this group. The results highlight the importance of determining species composition when devising control strategies for earth mite outbreaks.

Acari↗
PubMed2003

Toxicity of imidacloprid to Galendromus occidentalis, Neoseiulus fallacis and Amblyseius andersoni (Acari: Phytoseiidae) from hops in Washington State, USA.

The toxicity of systemic and spray formulations of imidacloprid to Galendromus occidentalis Nesbitt, Neoseiulus fallacis Garman and Amblyseius andersoni (Chant) from hop yards in Washington State was evaluated in laboratory bioassays. The field rate of imidacloprid for hop aphids (0.13 g a.i. l) was highly toxic (100% mortality) to G. occidentalis and N. fallacis but less so (35.6% mortality) to A. andersoni. Half and quarter rates were also highly toxic to G. occidentalis and N. fallacis (79.5-100% mortality) but again had lower toxicity to A. andersoni (8.2-31.3% mortality). Systemic toxicity (via consumption of spider mite motiles feeding on leaf discs cut from imidacloprid-treated (0.13 g a.i. l) dwarf bean plants) was also high for G. occidentalis (98.3% mortality), as was toxicity from dried residues (93-98% mortality). Residual toxicity to N. fallacis was also high (89% mortality). The significance of these results for biological control of spider mites in hops and other crops is discussed.

Acari↗
PubMed2003

Study of temperature-growth interactions of entomopathogenic fungi with potential for control of Varroa destructor (Acari: Mesostigmata) using a nonlinear model of poikilotherm development.

AIMS: To investigate the thermal biology of entomopathogenic fungi being examined as potential microbial control agents of Varroa destructor, an ectoparasite of the European honey bee Apis mellifera. METHODS AND RESULTS: Colony extension rates were measured at three temperatures (20, 30 and 35 degrees C) for 41 isolates of entomopathogenic fungi. All of the isolates grew at 20 and 30 degrees C but only 11 isolates grew at 35 degrees C. Twenty-two isolates were then selected on the basis of appreciable growth at 30-35 degrees C (the temperature range found within honey bee colonies) and/or infectivity to V. destructor, and their colony extension rates were measured at 10 temperatures (12.5-35 degrees C). This data were then fitted to Schoolfield et al. [J Theor Biol (1981)88:719-731] re-formulation of the Sharpe and DeMichele [J Theor Biol (1977)64:649-670] model of poikilotherm development. Overall, this model accounted for 87.6-93.9% of the data variance. Eleven isolates exhibited growth above 35 degrees C. The optimum temperatures for extension rate ranged from 22.9 to 31.2 degrees C. Only three isolates exhibited temperature optima above 30 degrees C. The super-optimum temperatures (temperature above the optimum at which the colony extension rate was 10% of the maximum rate) ranged from 31.9 to 43.2 degrees C. CONCLUSIONS: The thermal requirements of the isolates examined against V. destructor are well matched to the temperatures in the broodless areas of honey bee colonies, and a proportion of isolates, should also be able to function within drone brood areas. SIGNIFICANCE AND IMPACT OF THE STUDY: Potential exists for the control of V. destructor with entomopathogenic fungi in honey bee colonies. The methods employed in this study could be utilized in the selection of isolates for microbial control prior to screening for infectivity and could help in predicting the activity of a fungal control agent of V. destructor under fluctuating temperature conditions.

Acari↗
PubMed1990

Sites of attachment in Amblyomma triguttatum triguttatum Koch (Acari: Ixodidae) on natural hosts.

The sites of attachment of Amblyomma triguttatum truguttatum were studied from June to September 1981 on 146 feral pigs (Sus scrofa) and from March to August 1982 and January 1983 on 68 grey kangaroos (Macropus giganteus), naturally infested. Two hundred fifty hour (81%) of 314 nymphs were detected on the ears of the pigs; neither adults nor larvae of A. t. triguttatum were found on S. scrofa. Six hundred ninety four (97%) of 715 larvae; 283 (96%) of 295 nymphs and 11 (79%) of 14 adults of A. t. triguttatum were found on the ears of the kangaroos. The proportion of the larvae and nymphs on the ears of kangaroos and pigs respectively, decreased with the increase of tick load.

Acari↗
PubMed2004

Indoor winter fumigation of Apis mellifera (Hymenoptera: Apidae) colonies infested with Varroa destructor (Acari: Varroidae) with formic acid is a potential control alternative in northern climates.

Formic acid treatment for the control of the ectoparasitic varroa mite, Varroa destructor Anderson & Trueman, infesting honey bee, Apis mellifera L., colonies is usually carried out as an in-hive outdoor treatment. This study examined the use of formic acid on wintered colonies kept indoors at 5 degrees C from 24 November 1999 to 24 March 2000. Colonies were placed in small treatment rooms that were not treated (control) or fumigated at three different concentrations of formic acid: low (mean 11.9 +/- 1.2 ppm), medium (mean 25.8 +/- 1.4 ppm), or high (mean 41.2 +/- 3.3 ppm), for 48 h on 22-24 January 2000. Queen bee, worker bee, and varroa mite mortality were monitored throughout the winter, and tracheal mite, Acarapis woodi (Rennie), prevalence and mean abundance of nosema, Nosema apis Zander, spores were assessed. This study revealed that formic acid fumigation of indoor-wintered honey bees is feasible and effective. The highest concentration significantly reduced the mean abundance of varroa mites and nosema spores without increasing bee mortality. Tracheal mite prevalence did not change significantly at any concentration, although we did not measure mortality directly. The highest concentration treatment killed 33.3% of queens compared with 4.8% loss in the control. Repeated fumigation periods at high concentrations or extended fumigation at low concentrations may increase the efficacy of this treatment method and should be tested in future studies. An understanding of the cause of queen loss and methods to prevent it must be developed for this method to be generally accepted.

Acari↗
PubMed2004

Altered physiology in worker honey bees (Hymenoptera: Apidae) infested with the mite Varroa destructor (Acari: Varroidae): a factor in colony loss during overwintering?

The ectoparasitic mite Varroa destructor (Anderson & Trueman) is the most destructive pest of the honey bee, Apis mellifera L., in Europe and the United States. In temperate zones, the main losses of colonies from the mites occur during colony overwintering. To obtain a deeper knowledge of this phenomenon, we studied the mites' impact on the vitellogenin titer, the total protein stores in the hemolymph, the hemocyte characteristics, and the ecdysteroid titer of adult honey bees. These physiological characteristics are indicators of long-time survival and endocrine function, and we show that they change if bees have been infested by mites during the pupal stage. Compared with noninfested workers, adult bees infested as pupae do not fully develop physiological features typical of long-lived wintering bees. Management procedures designed to kill V. destructor in late autumn may thus fail to prevent losses of colonies because many of the adult bees are no longer able to survive until spring. Beekeepers in temperate climates should therefore combine late autumn management strategies with treatment protocols that keep the mite population at low levels before and during the period when the winter bees emerge.

Acari↗