Frantisek Dusbabek

Winter infestation of wild birds by ticks and chiggers (Acari: Ixodidae, Trombiculidae) in the Czech Republic.

In winter months during 2003–2006, wild birds were captured and examined for ticks and chiggers at two sites near Brno, Czech Republic. In total, 1,362 birds, mostly passerines, were examined. The tick Ixodes arboricola Schulze et Schlottke, 1929 was found on 47 (3%) birds of six species. Ixodes ricinus Linnaeus, 1758 was found on 11 (1%) birds of five species. Larvae of chiggers Ascoschoengastia latyshevi (Schluger 1955) were found on 13 (1%) birds of six species. I. arboricola and A. latyshevi associated with hole-nesting birds can appear on birds rather frequently even during winter months. I. ricinus occurs on birds in winter sporadically.

Determination of purine bases and nucleosides by conventional microbore high-performance liquid chromatography and gas chromatography with an ion-trap detector

A reversed-phase high-performance liquid chromatographic method has been developed for the analysis of purine and pyrimidine bases, uric acid and nucleosides largely relating to the purine synthetic and degradation metabolic pathways, with particular attention to the separation of hypoxanthine, xanthine and guanine. Complete separation and quantitation of the purines has been accomplished in the nanogram-microgram scale on conventional 4.6 mm I.D. columns with a standard gradient HPLC instrumentation as well as on 1 mm I.D. microbore columns with a dedicated isocratic micro-HPLC system using a dioxane-sodium acetate buffer. For the definite identification of components in excreta of ticks a GC-MS method has been described involving formation and GC of the trimethysilyl derivatives on a 25-m DB-5 column directly coupled with an ion trap detector. The methods are demonstrated on the analysis of the purine metabolites having an assembly pheromone effect on argasid ticks.

The effect of feeding status on sexual attractiveness of Ixodes ricinus (Acari: Ixodidae) females

Sexual attractiveness of unengorged, semiengorged and fully engorged females of both field and laboratory populations of Ixodes ricinus was studied under laboratory conditions by means of a computerised video tracking system. A male and a female were allowed to walk freely in a glass arena during 1 h and their behavioural interactions were observed. Obtained results revealed that the feeding status of I. ricinus females affects their sexual attractiveness. The highest attractiveness was observed in engorged females, the lowest in unengorged females of the field population. Copulation occurred in all experimental groups with the highest frequency observed in the unengorged virgin laboratory females. Despite engorged females being highly attractive for males on distance, the frequency of copulation was low. Differences between field and laboratory populations were found in both behavioural parameters and frequency of copulation.

A review of mites of the genus Neharpyrhynchus Fain (Acari: Harpirhynchidae) — ectoparasites of wild birds, including description of four new species

Abstract Seven species of the genus Neharpyrhynchus Fain, 1972 (Acari: Harpirhynchidae) are recorded on European birds, including four described in this paper as new: TV. bochkovi n. sp., N. pari n. sp., N. schoenobaenus n. sp. and N spinus n. sp. Based on external morphology of European species, as well as of the extraeuropean species N. baile (Bochkov, Literak and Capek, 2007), N squamiferus (Fain, 1972) and N. trochilinus (Fain, 1972), five species groups (i.e., N baile group, N. hippolae group, N pilirostris group, N. plumaris group and N. squamiferus group) are described. The prevalence of bird infestation by individual European Neharpyrhynchus species is defined according to recent field examinations in the Czech Republic and on the border between Slovakia and Poland. A key for determining females of all known species is included.

Three species of the genus Pellonyssus (Acari: Macronyssidae) including a new species from Costa Rican birds

Abstract Three species of the genus Pellonyssus Clark and Yunker, 1956 are reported from Costa Rican birds: Pellonyssus gorgasi Yunker and Radovsky 1966 from Threnetes ruckeri (Bourcier) (Trochilidae); Pellonyssus marui Yunker and Radovsky, 1966 from Manacus candei (Parzudaki) (Pipridae); and Pellonyssus cyanoides Dusbabek and Literak n. sp. from Cyanocompsa cyanoides (Lafresnaye) (Cardinalidae) Figures of female P. marui and of male P. cyanoides Dusbabek and Literak n. sp . are included.

Methyl 3-chloro-4-methoxybenzoate, a new candidate semiochemical inhibiting copulation behaviour of Ixodes ricinus (L.) males

Abstract.  Females of Ixodes ricinus (L. 1758) emit several semiochemicals influencing copulatory behaviour in males. One of these candidate compounds, methyl 3‐chloro‐4‐methoxybenzoate, is emitted exclusively by engorged females, and shows a copulation inhibiting effect in males. In Y‐tube experiments, the synthetic analogue of this compound at a concentration of 100 µg/mL in ethanol, attracted males in only 25.6% of tests, whereas it repelled them in 74.4% of cases. However, unengorged females do not respond to this substance at all. The number of contacts between males and unengorged females treated with methyl 3‐chloro‐4‐methoxybenzoate (250 µg/mL in ethanol, 1 µL per female) decreases to 28% compared to a control level of 80%, and the percentage of copulating pairs decreases to 12% compared to control (49%) over 2 h. Possibly, a fertilized engorged female with mature eggs uses this semiochemical to send a signal to males indicating that another copulation is no longer needed.

Lasioseius aquilarum n. sp. (Acari: Ascidae) from the nares of costa rican hummingbirds (Trochilidae)

Abstract The female of a new species, Lasioseius aquilarum n. sp. (Acari: Ascidae), is described and illustrated. It belongs to the L. drosophili group according to Kargs (1980) classification and represents the fourth species in the genus known from hummingbirds and hummingbird pollinated flowers. It is the first record of the genus in Costa Rica (Central America).

Adaptation of mites and ticks to parasitism. Medical and veterinary aspects

Acari are the only group among Chelicerata which includes plant and animal parasites. The ancestors of zooparasites probably were nest inhabiting and free living predators and keratinophages, or phoretic species. They developed (1) adaptations to host location and identification, (2) adaptations to attachment on the host body, (3) adaptations to blood feeding and digestion, and (4) adaptations to host defense mechanisms.

Cuticular hydrocarbon variation and progeny phenotypic similarity between laboratory breeds of allopatric populations of Argas (Persicargas) persicus (Oken) (acari: Argasidae)

Cuticular hydrocarbons of laboratory breeds of four Argas (Persicargas) persicus (Oken) population samples were studied by gas chromatography. Cuticular hydrocarbon patterns were used to determine Neis genetic distances among populations, and their average heterozygosity. Sixteen n-alkanes, 37 monomethylalkanes and 26 dimethylalkanes were identified. Mostly quantitative differences were recorded between populations, rarely among males and females of the same population. A low genetic distance (0.0278-0.0781) together with a prominent degree of average heterozygosity (60.37-66.98%) were recorded in the population samples studied. When crossbreeds with adult specimens from the same or different geographical origins are performed, all larval progenies closely correlated within themselves and with their parents in hydrocarbon pattern. A slight matrocliny occurred in larvae coming from crosses of the same geographical source. From cross data it is postulated that hydrocarbons in A. persicus are inherited under a two dominant alleles hypothesis.