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Start Over Creator Dusbábek, František

2. Chemical stability of assembly pheromone of argasid ticks (Ixodoidea: Argasidae)

Creator:
Dusbábek, František, Zahradníčková, Helena, and Šimek, Petr
Format:
print
Type:
model:internalpart and TEXT
Subject:
assembly pheromone, guanine, xanthine, hypoxanthine, uric acid, tick excreta, purine degradation, Argas persicus, and Omithodoros moubata
Language:
English
Description:
Chemical stability and aggregation activity of assembly pheromone of argasid ticks and its synthetic purine analogues were studied during long-lasting storage at room temperature as the potential components of attractant/acaricide mixtures. Guanine spherules from dry excreta of Omithodoros moubata Murray, 1877 were very stable in their chemical composition and did not suffer from purine degradation. However, an intensive purine conversion into uric acid occurred in samples of the fluid of the excreta of Argas persicus (Oken, 1818) and to a lesser extent also in an artificial mixture of synthetic guanine, xanthine and hypoxanthine in saline. The presence of bacteria Bacillus sp. and the moulds Talaromyces flavus (syn. Pénicillium dangeardii) and Aspergillus carbonarius, isolated from some samples, might explain the enzymic degradation of purines. The suspension of guanine hydrochloride in saline or in saline with ethanol (1 : 1 v/v) as a potential acaricide solvent, and with diatomaceous earth as the pheromone carrier, was very stable and no guanine degradation occurred. This proved to be suitable for potential use mixed with acaricides for tick control. The assembly of A. persicus males, on most of the substrates tested, was very high up to day 77 of experiment but decreased significantly on day 114-119 in samples of synthetic analogue of assembly pheromone variant 1 in which the absolute amount of guanine in solutions strongly decreased or disappeared completely.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Málo známí cizopasníci ptáků - roztoči čeledi Harpirhynchidae

Creator:
Literák, Ivan, Bochkov, Andre, Dusbábek, František, Martinů, Jana, Podzemný, Petr, and Sychra, Oldřich
Type:
article and TEXT
Language:
Czech
Description:
Roztoči z čeledi Harpirhynchidae žijí parazitickým způsobem na těle u řady druhů ptáků. Zástupci rodu Harpirhynchus tvoří makroskopicky zřetelné kožní cysty lokalizované pod křídly. H. nidulans tvoří cysty u dlasků tlustozobých a H. dusbabeki u sýkořic vousatých. Identifikováno bylo několik dalších druhů a rodů u různých skupin ptáků a protože jsou tito parazité hostitelsky specifičtí, lze očekávat nálezy dalších dosud neznámých druhů. and Mites from the family Harpirhynchidae are permanent highly specialized skin-dwelling bird parasites. The representatives of the genus Harpirhynchus create macroscopic voluminous cutaneous cysts located mainly at the base of the wings. In various bird species and genera, some new species from the family studied have been identified. Because these parasites are host-specific, more hitherto unknown species are expected to be found.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

4. Nymphal sexual dimorphism in the sheep tick Ixodes ricinus (Acari: Ixodidae)

Creator:
Dusbábek, František
Format:
print
Type:
model:internalpart and TEXT
Subject:
Ixodes ricinus, sheep tick, nymphs, sexual dimorphism, morphology, and development
Language:
English
Description:
Unfed nymphs of Ixodes ricinus (L.) can be divided into two morphological groups according to the length of idioso-ma, scutum, hypostome and palpal segment III, and the number of dorsal alloscutal setae. Specimens of greater body dimensions and more numerous dorsal alloscutal setae moulted predominantly into females. The frequency of different nymphal length categories in field-collected ticks followed a normal distribution. The length of unfed nymphs correlates well with the length (r = 0.7248 ± 0.0711, P < 0.001) and weight (r = 0.6519 ± 0.0782, P < 0.001) of engorged nymphs, however, it varies in ticks of different origin. In field-collected ticks, freshly engorged female nymphs were 2.30-2.94 mm long, male nymphs 2.14-2.46 mm long. Feeding period (P < 0.05) and premoulting period (P < 0,001 ) were significantly longer in female nymphs both in field-collected and laboratory-derived I. ricinus. The engorgement weight was found to be the best criterion for differentiation of male and female nymphs of ixodid ticks. In field-collected nymphs engorged on BALB/c mice, 98.6 % of females moulted from nymphs weighting more than 3.60 mg, while in laboratory-derived ticks, 98.4 % of females emerged from nymphs of 3.42 mg body mass or more.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public