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At least 109 records · Page 6Linked to original sources
PubMed2004

Gigantolaelaps gilmorei Fonseca, 1939 (Acari: Laelapidae): taxonomic status, lectotype and paralectotype designation and new distributional records.

A lectotype series is designated for Gigantolaelaps gilmorei Fonseca, 1939 in the Acari Collection of the Instituto Butantan in Sao Paulo, Brazil. This laelapid mite species has a widespread geographical distribution. We report a close association with Oryzomys russatus (Wagner) in southeastern Brazil and Argentina, the most southerly part of its range. In Paraguay, the primary host is O. nitidus (Thomas).

Animals↗
PubMed2001

Interspecific and geographical variation in the sequence of rDNA expansion segment D3 of Ixodes ticks (Acari: Ixodidae).

The base sequence of the rDNA D3 expansion segment and flanking H14 stem varies between six species of Ixodes ticks (Acari: Ixodidae) where only 33 invariant sites occur among sequences of 123-203 bases in length. Multiple copies of D3 were sequenced from localities across the geographical ranges of four species to investigate deep population genetic structure. Two species, I. pacificus, from western North America, and I. ricinus, from Europe, have no sequence variation indicating a lack of deep genetic structure. One species, I. scapularis, from eastern North America has two forms of the D3 sequence that are distributed differently among northern vs. southern populations, suggesting recent divergence and hybridization. I. persulcatus, from Eurasia, has sequence variation between localities of the order of that observed between other species, suggesting a long history of population isolation and deep genetic structure. With the exception of I. scapularis, sequence variation was not observed within localities. This indicates that cellular processes underpinning concerted evolution have homogenized populations and species for particular rDNA sequence variants.

Animals↗
PubMed2000

Cloning and transcriptional expression of a leucokinin-like peptide receptor from the southern cattle tick, Boophilus microplus (Acari: Ixodidae).

Leucokinins are invertebrate neuropeptides that exhibit myotropic and diuretic activity. Only one leucokinin-like peptide receptor is known, the lymnokinin receptor from the mollusc Lymnaea stagnalis. A cDNA encoding a leucokinin-like peptide receptor was cloned from the Southern cattle tick, Boophilus microplus, a pest of cattle world-wide. This is the first neuropeptide receptor known from the Acari and the second known in the subfamily of leucokinin-like peptide G-protein-coupled receptors. The deduced amino acid sequence exhibits 40% identity to the lymnokinin receptor. The receptor transcript is present in all tick life stages as determined by semiquantitative reverse transcription polymerase chain reaction. We also propose that the sequence AAF50775.1 from the Drosophila melanogaster genome (CG10626) encodes the first identified insect leucokinin receptor.

Amino Acid Sequence↗
PubMed2003

Functional analysis of a G protein-coupled receptor from the southern cattle tick Boophilus microplus (Acari: Ixodidae) identifies it as the first arthropod myokinin receptor.

The myokinins are invertebrate neuropeptides with myotropic and diuretic activity. The lymnokinin receptor from the snail Lymnaea stagnalis (Mollusca) has been the only previously identified myokinin receptor. We had cloned a G protein-coupled receptor (AF228521) from the tick Boophilus microplus (Arthropoda: Acari), 40% identical to the lymnokinin receptor, that we have now expressed in CHO-K1 cells. Myokinins at nanomolar concentrations induced intracellular calcium release, as measured by fluorescent cytometry and the receptor coupled to a pertussis toxin-insensitive G protein. Absence of extracellular calcium did not inhibit the fluorescence response, indicating that intracellular stores were sufficient for the initial response. Control cells only transfected with vector did not respond. We conclude that the tick receptor is the first myokinin receptor to be cloned from an arthropod.

Amino Acid Sequence↗
PubMed2003

A new species of parasitic mites of the genus Syringophiloidus Kethley 1970 (Acari: Syringophilidae) from the barn swallow Hirundo rustica Linnaeus, 1758.

A new quill mite species Syringophiloidus hirundinis (Acari: Syringophilidae) is described from the Barn Swallow Hirundo rustica. The species Syringophiloidus hirundinis had a prevalence of 17.1% in the two outermost tail feathers (N = 208 adult Barn Swallows) during the breeding season of the Barn Swallow host. Intensity of infestation was 9.7 adult mites per pair of infested tail feathers. The sex ratio was highly biased towards females, with only 7.5% of all individuals being males (20:3).

Animals↗
PubMed1993

Investigation of the validity of species status of Ixodes dammini (Acari: Ixodidae) using rDNA.

The two internal transcribed spacers (ITS1 and ITS2) of rDNA of three members of the Ixodes ricinus "complex" (Acari: Ixodidae) were sequenced. Sequence variation was assessed for the North American species I. scapularis, I. dammini, and I. pacificus at three levels: within individual/population, between individuals of different geographic origin within a species, and between species. Both spacers are highly variable, particularly with regard to small deletions and additions which may arise via replication slippage. Homogenization of rDNA multigene arrays for particular sequence variants appears to occur at a relatively rapid rate, since I. pacificus sequences differ from the others at numerous invariant sites, facilitating the use of these sequences to assess sibling species relationships. Based on maximum parsimony and two distance methods (unweighted pair-group with arithmetic means and neighbor-joining), sequence variation in ITS1 and ITS2 suggests that I. scapularis and I. dammini are not distinct species and that even individuals from geographically isolated locations are very similar. Individuals from geographically separated populations of I. pacificus appear to be relatively less closely related to each other but distinct from those of I. scapularis/dammini. In I. scapularis/dammini, diversity within and between individuals from geographic populations contributed equally to total sequence diversity.

Animals↗
PubMed1992

Control of the straw itch mite (Acari: Pyemotidae) with sulfur in an insect rearing facility.

The ectoparasitic mite Pyemotes tritici (Lagrèze-Fossat & Montané) (Acari: Pyemotidae) caused paralysis and reduced longevity in eucalyptus longhorned borer, Phoracantha semipunctata F., under laboratory rearing conditions. Application of dusting sulfur to logs that contained pupating borers greatly reduced densities of mites on emerging adult beetles and increased beetle survivorship. Uniform application to all logs in a glasshouse effectively eradicated the mite infestation. A bioassay showed that sulfur may physically impede the dispersal of immature mites by adhering to the cuticle, but sulfur vapor did not act as a toxin.

Animals↗
PubMed2004

Beat sampling accuracy in estimating spruce spider mite (Acari: Tetranychidae) populations and injury on juniper.

The use of a standardized beat sampling method for estimating spruce spider mite, Oligonychus ununguis (Jacobi) (Acari: Tetranychidae), densities on a widely used evergreen ornamental plant species, Juniperus chinensis variety 'Sargentii' A. Henry (Cupressaceae), was examined. There was a significant positive relationship between total spruce spider mite densities and spider mite densities from beat sampling on juniper. The slope and intercept of the relationship may be used by pest managers to predict total spider mite densities on plants from beat sample counts. Beat sampling dramatically underestimates the total number of spider mites on a foliage sample. The relationships between spruce spider mite feeding injury and spider mite density estimates from beat sampling juniper foliage and total spider mite counts on foliage were also examined. There was a significant positive relationship between spruce spider mite density as estimated from beat sampling and injury to the plants. There was a similar positive relationship between the total number of spruce spider mites and injury to the plants, suggesting that a pest manager could use beat sampling counts to estimate plant injury and related thresholds. These findings have important implications to decision-making for spruce spider mite control, especially as it relates to threshold levels and determining rates of predator releases. Further assessment of the effectiveness of beat and other sampling methods across multiple spider mite- host plant associations needs to be examined to enable pest managers to select sampling plans that are feasible and reliable.

Animals↗
PubMed2004

Acaricidal activities of extracts of Stellera chamaejasme against Tetranychus viennensis (Acari: Tetranychidae).

Extracts of a perennial and poisonous weed, Stellera chamaejasme L. (Thymelaeaceae) were bioassayed to determine their acaricidal activities against Tetranychus viennensis Zacher (Acari: Tetranychidae) in the laboratory. Extracts had both contact and systemic toxicity to the mite. After liquid chromatography and thin layer chromatography, the extract was further concentrated, separated, and bioassayed. This study is the first to report the acaricidal property of S. chamaejasme and its potential as a botanical pest control agent.

Insecticides↗
PubMed2005

Effects of soil moisture and temperature on reproduction and development of twospotted spider mite (Acari: Tetranychidae) in strawberries.

The effects of soil moisture and temperature on the reproduction of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), were examined in laboratory and field tests in strawberries, Fragaria x ananassa Duchesne, in Florida. Different soil moisture levels (low, moderate, and high) were compared to determine how soil moisture affects the reproduction and development of twospotted spider mite. In addition to soil moisture, different irrigation techniques (drip versus drip/overhead) were compared to determine their effects on twospotted spider mite reproduction as well as the incidence of angular leaf spot, Xanthomonas fragaria Kennedy & King disease. Similar studies were conducted to determine how different temperatures (18, 27, and 35 degrees C) affect the reproduction and development of twospotted spider mites. In the laboratory, low soil moisture as well as temperatures >27 degrees C promoted twospotted spider mite development. A similar trend was observed in a field study with low soil moisture promoting twospotted spider mite reproduction during the early season (11 November--8 December). Irrespective of moisture levels, a significantly higher incidence of X. fragaria was recorded in treatments with drip/overhead irrigation systems compared with drip irrigation. Implications for management of soil moisture levels are discussed with respect to the abundance of twospotted spider mite and X. fragaria in strawberries.

Agriculture↗
PubMed1990

Taxonomic relationships of the subgenus Rhipistoma (Acari: Ixodidae: Haemaphysalis).

The possible evolution of the haemaphysalid subgenus Rhipistoma (Koch) (Acari: Ixodidae, Haemaphysalis) is postulated. H. hispanica and H. caucasica seem to be the most primitive species of the subgenus, closely related to a common ancestor, as can be deduced from the palpal outline and from the combination of spines and spurs on the coxae and palpi. However, H. adleri, H. asiatica, H. fossae, H. eupleres, and H. obtusa compose a group of phylogenetically more-advanced species, based on the development of complex palpal structures in the adults, but which have also retained some of the more primitive characteristics in the immature stages. An evolutionary line containing many species seems to have developed from the subgroup H. hispanica (bequaerti, cooleyi, hyracophila, calcarata, and houyi), as inferred from the morphological features of the palpi. The data from lemuris suggest a distant relationship with the H. asiatica group. H. bartelsi and H. koningsbergeri seem to have evolved from a common ancestor of the subgenus (or even from the subgroup hispanica) because they share primitive morphological characteristics. Also, H. heinrichi and H. indica may be considered as two modern members within the indica subgroup, from which H. canestrinii seems to have originated. The data from the canestrinii group suggest the existence of a relationship between the indica-heinrichi-canestrinii subgroup, spinulosa subgroup and leachi subgroup, because they share many morphological features. H. bartelsi and H. koningsbergeri would remain as two species of a primitive pathway from the common ancestor of the subgenus, evolving to the canestrinii subgroup. H. erinacei and its subspecies form a group with several primitive features, linking it to the subgenus Ornithophysalis. Also, H. pedetes and H. zumpti are two very similar species that appear to have evolved from an arinacei-like ancestor. It seems possible that the leachi and spinulosa subgroups have evolved from a complex of species included today in the spinulosa and canestrinii subgroups.

Animals↗
PubMed1990

Bioenergetic consequences of alopecia induced by Dermacentor albipictus (Acari: Ixodidae) on moose.

Fasting metabolic rates, respiration rates, respiratory minute volumes, and fasted weights were measured on three yearling moose (Alces alces (L.)) (Artiodactyla: Cervidae) infested with 50,000 winter ticks. Dermacentor albipictus (Packard) (Acari: Ixodidae), and on two uninfested controls. Infestations produced no detectable effects on fasting metabolic rates or weight changes. The influence of tick-induced alopecia on lower critical temperatures could not be assessed because of warm temperatures during the winter and spring trials. Destruction of winter hair accompanied a reduction in respiratory minute volumes and respiration rates of heat-stressed moose.

Alopecia↗
PubMed1991

Laboratory biology of Hyalomma truncatum (Acari: Ixodidae).

The life cycle of Hyalomma truncatum Koch (Acari: Ixodidae) required an average of 108 d at 26 +/- 1 degree C. 92-96% RH, and a 12:12 (L:D) photoperiod to complete. Mean weights of unfed larvae, nymphs, and females were 0.02, 0.19, and 11.1 mg, respectively. Weight of larvae, nymphs, and females increased 20-, 91-, and 48-fold, respectively, as a result of feeding on guinea pigs. All stages exhibited host-seeking behavior less than 1 d after emergence. The mean (+/- SE) feeding period of larvae, nymphs, and adults was 3.8 (+/- 0.1), 7.7 (+/- 0.3), and 8.3 (+/- 0.3) d, respectively. Larvae and nymphs molted an average of 11.0 (+/- 0.3), and 30.7 (+/- 0.2) d after engorgement, respectively. The female/male sex ratio, as determined from emerged adults, was 1.4:1. Oviposition started an average of 11.9 (+/- 0.8) d after engorgement, and a mean of 6.701 eggs per female was deposited. A total of only 48% of the eggs enclosed after a mean incubation of 35 (+/- 1.1) d. Females converted 56% of their engorged weight into eggs and produced an average of 12,614 (+/- 2.0) eggs/g of engorged body weight. On the first day of oviposition, an egg less than 24 h old weighed an average of 44.8 (+/- 1.5) micrograms. Egg weight was significantly (P less than 0.01) lower during peak egg production (days 2-8 after onset of oviposition) than during reduced egg production (days 14-20 after onset of oviposition).

Animals↗
PubMed1993

Distribution and seasonal and diurnal activity patterns of Eutrombicula alfreddugesi (Acari: Trombiculidae) in a forest edge ecosystem.

Microclimatic and vegetative effects on the population size and activity patterns of larval Eutrombicula alfreddugesi Oudemans, 1910 (Acari: Trombiculidae), were investigated in Nebraska between latitude 40 degrees 0'0" N and 40 degrees 1'21" N. Larval population densities along a forest edge were greatest in areas of high relative humidity, moderate temperature, low incident sunlight, and increasing substrate vegetation. Although chigger populations existed throughout the forest edge, larger populations concentrated in short- to tall-grass transition zones. Chiggers were rarely found in the undergrowth beneath the tree canopy. Chigger activity correlated with a microclimatically driven diurnal rhythm. Activity was greatest during the late afternoon-early evening, between 1530 and 1930 hours (CDST). Larval activity dropped to low levels and remained so until sunrise; this period of reduced activity occurred between 1930 and 0530 hours. Small increases in larval activity occurred around sunrise (approximately 0600-0700 hours). Between about 0700 and 1530 hours, larval E. alfreddugesi were inactive and did not respond to normal sampling stimuli. Larval populations appeared in late April through early May, peaked in abundance in late June and early July, diminished through late summer, and disappeared in midautumn as the ground began to freeze.

Animals↗
PubMed1994

Aponomma (Bothriocroton) glebopalma, n. subgen., n. sp., and Amblyomma glauerti n. sp. (Acari: Ixodida: Ixodidae), parasites of monitor lizards (Varanidae) in Australia.

Aponomma (Bothriocroton) glebopalma, n. subgen., n. sp., and Amblyomma glauerti, n. sp. (Acari: Ixodidae), are described from the monitor lizards Varanus glebopalma Mitchell and Varanus glauerti Mertens in Western Australia and the Northern Territory, Australia. The new subgenus is erected to accomodate A. (Bothriocroton) glebopalma, a new species with a deeply pitted and pilose scutum in both the adult and immature stages, unlike all other described species of Aponomma. This new species is found in an area where Aponomma fimbriatum Koch, a parasite of varanid lizards and various species of snakes, was the only known member of the genus found in both Western Australia and the Northern Territory. Amblyomma glauerti n. sp., an ornate Australian reptile tick found on the same two hosts in Western Australia and the Northern Territory, is also described. These two new species were recovered from formalin-preserved lizard specimens; therefore, nothing is known of their life cycles, except that all stages parasitize varanid lizards.

Animals↗
PubMed1994

Host-seeking of blacklegged tick (Acari: Ixodidae) nymphs and adults at the woods-pasture interface.

To clarify the risk of pastured livestock for exposure to Ixodes scapularis Say (Acari: Ixodidae), we estimated the host-seeking activity of nymph and adult blacklegged ticks at the woods-pasture interface on horse farms in Maryland. Parallel linear transects of 100 m length and 1 m width were sampled repeatedly in pastures and adjacent woodland locations during periods of nymph (early summer) and adult (fall and spring) host-seeking activity. Data collected over two successive years indicated that adults were most abundant in ecotonal vegetation at the wood's edge, median values of 6.4 and 2.2 ticks per 100 m2 sample during fall and 1.2 and 0.5 ticks per 100 m2 sample for spring periods. Nymphs were most abundant in the shallow woods location, median values of 4.2 and 35 ticks per 100 m2 sample, followed by the deep woods and wood's edge locations. Host-seeking nymph and adult black-legged ticks also were collected repeatedly in pasture vegetation, median values ranging from 0.2-0.8 ticks per 100 m2 sample, with a progressive decrease in abundance from the fenceline into pasture. Adults and nymphs both were uncommon more than 5 m into pastures, where only two adults and one nymph were captured in 84 (fall and spring) and 24 (summer) 100-m2 samples, respectively. Levels of adult and nymph host-seeking in pasture vegetation were spatially correlated with tick abundance in adjacent woodlands when ticks were numerous; this condition presumably reflects a spillover of ticks from the woodlands-based population. These findings expand knowledge of black-legged tick host-seeking behavior and establish a basis for the exposure of pastured livestock to nymphs and adults.

Aging↗
PubMed2005

First record of hosts for tick Carios kelleyi (Acari: Ixodida: Argasidae) in Canada and Montana.

I found Carios kelleyi Cooley & Kohls (formerly Ornithodoros kelleyi) (Acari: Ixodida: Argasidae) on five species of bats (Eptesicusfuscus, Myotis lucifugus, Myotis ciliolabrum, Myotis evotis, and Myotis volans) in the prairies of southeastern Alberta and north central Montana. This is the first occurrence of ticks on bats in Canada. This is also the first record of C. kelleyi on M. evotis and M. volans. Dates of parasitization ranged from 22 May to 17 October, and the number of ticks per host ranged from 1 to 44 (median two ticks per host). Number of parasitized individuals was significantly higher in rock-roosting E. fuscus compared with building-roosting E. fuscus, rock- and building-roosting M. lucifugus, and rock-roosting M. ciliolabrum and M. evotis. A significant sex bias was noted in rock-roosting E. fuscus in 2000 with significantly more females parasitized. The number of ticks per bat host was highest in 2001, corresponding to the driest and hottest summer of the survey.

Animals↗