Search results for "Louse"
showing 10 items of 41 documents
Control of freshwater fish louse Argulus coregoni: a step towards an integrated management strategy
2008
Harmful infections by ectoparasites of the genus Argulus occur repeatedly in freshwa- ter fish farming operations where the management has largely been ineffective. Preventative meth- ods and regular monitoring are rarely applied, so that chemical interventions become necessary. According to the Integrated Pest Management (IPM) approach, a sustainable management or control program for a parasite should be based on knowledge of the ecology of the parasite along with adop- tion of several prevention and control methods, the application of which is dependent upon the pre- vailing infection level. The application of multiple management tactics is especially important because parasites can devel…
The Song of the Crusade against the Albigensians (1st quarter of the 13th century) and the Treaty of Meaux-Paris (1228). Literary mimesis and legal c…
2020
En aquest article analitzem els mecanismes de la construcció del relat (oficial), des de diversos punts de vista, de la Croada contra els albigesos i l’expoli d’Occitània per França en el transcurs d’aqueixa cruel campanya militar (1r terç del segle XIII). Analitzarem dues fonts textuals que són testimonis d’excepció dels fets i de la construcció i la narració d’aqueix relat, a través de la mimesi historiogràfica en un cas, la Cançó de la Croada contra els albigesos, i, en l’altre, del formalisme d’un text jurídic (document històric, pròpiament dit) del més alt rang, el Tractat de Meux-París (1229), signat pels màxims representants de les dues contraparts. I també analitzarem qui es benefic…
Life begins when the sea lion is ashore: microhabitat use by a louse living on a diving mammal host
2012
AbstractAmong Anoplura, the family Echinophthiriidae includes species that infest pinnipeds and otters. Previous evidence obtained from pinnipeds infested by echinophthiriids, specifically from seals, indicates that flippers are the preferred infestation sites, while lice from fur seals select areas in the pelage. We studied habitat selection of Antarctophthirus microchir on South American sea lion pups (Otaria flavescens Shaw, 1800) from Patagonia, Argentina, during the austral summer of 2009. We found a clear pattern of habitat selection: eggs are laid on the dorsal surface; nymphs 1 hatch there and then migrate to the belly, where they develop into adults and copulate; and then ovigerous…
A cost of Wolbachia-induced sex reversal and female-biased sex ratios: decrease in female fertility after sperm depletion in a terrestrial isopod.
2004
A number of parasites are vertically transmitted to new host generations via female eggs. In such cases, host reproduction is an intimate component of parasite fitness and no cost of the infection on host reproduction is expected to evolve. A number of these parasites distort host sex ratios towards females, thereby increasing either parasite fitness or the proportion of the host that transmit the parasite. In terrestrial isopods (woodlice), Wolbachia bacteria are responsible for sex reversion and female-biased sex ratios, changing genetic males into functional neo-females. Although sex ratio distortion is a powerful means for parasites to increase in frequency in host populations, it also …
Population dynamics of Antarctophthirus microchir (Anoplura: Echinophthiriidae) in pups from South American sea lion, Otaria flavescens, in Northern …
2009
We analysed population dynamics of the louse Antarctophthirus microchir in pups of the South American sea lion, Otaria flavescens, at the Punta León rookery (Argentina) over a period of 2 years. A total of 136 pups were aged and marked at the beginning of the lactation period ashore, then sampled for lice at different times within 30 days. Sampling was restricted to the chest and belly, two sites where lice were especially abundant. This concentration on ventral areas might protect lice from thermal stress in the austral summer. Infestation patterns in pups ≤3 days old suggested that the potential for transmission increased from first nymphs to adults. Population trends of each instar with …
Scanning electron microscopy of Antarctophthirus microchir (Phthiraptera: Anoplura: Echinophthiriidae): Studying morphological adaptations to aquatic…
2012
The members of the Family Echinophthiriidae (Phthiraptera: Anoplura) are unique among insects because they infest hosts with an amphibious lifestyle. During their evolution they developed morphological traits that are reflected in unique features. The SEM is a helpful tool to analyze them. Knowing in detail the external structure of these lice is the first step to understand the whole process that derived from the co-adaptation of lice and pinnipeds to the marine environment. For the first time, we studied the external structure of all stages of an echinophthiriid louse. The results are discussed in the light of their evolutionary, functional, and ecological implications. Fil: Leonardi, Mar…
Pedicularis sylvatica L. (19. Jahrhundert)
1847
3 meža jāņeglītes 19. gadsimta eksikāti. 1.attēls - legit Neuman; 2.attēls - legit Neuman, atradne "Germania"; 3.attēls - ievākts 1847. gadā. / 3 Wald-Läusekraut Herbarien aus dem 19. Jahrhundert. Bild 1 - legit Neuman; Bild 2 - legit Neuman, Hinterlegung "Germania"; Bild 3 - in Jahre 1847 gesammelt. / 3 19th century wood lousewort's herbariums. Picture 1 - legit Neuman; Picture 2 - legit Neuman, deposit "Germania"; Picture 3 - collected in 1847. [Attēli no LU Muzeja kolekcijas Herbarium Latvicum (RIG II); (BOT1371)]
Meža jāņeglītes pirmais atradums Latvijā
2021
Raksts veltīts Latvijā reti sastapta auga meža jāņeglītes Pedicularis sylvatica atradumiem Latvijas teritorījā, izceļot tās pirmo atradumu, ko 1923. gadā veica latviešu botāniķis Pauls Galenieks (1891 - 1962). Rakstā sniegta informācija par meža jāņeglītes herbārijiem Latvijas Universitātes muzejā.
Pedicularis sylvatica L. (P. Lackschewitz)
1928
Paula Lakševica 1928. gadā Rucavā ievāktie meža jāņeglītes exikāti. / Die Exikte des Wald-Läusekraut, die 1928 in Rucava Paul Lackschewitz gesammelt wurden. / Wood lousewort's Exicts, were collected in Rucava Paul Lackschewitz in 1928. [Attēli no LU Muzeja kolekcijas Herbarium Lackschewitzi (RIG III); (BOT12097)]
Pedicularis sylvatica L. (P. Galenieks)
1923
Meža jāņeglītes pirmais atradums Latvijā. Atradne Kurzemē, Rucavā starp Visminu un Zirnāju Vizuļu mājām gar kalnu, sausā vietā. / Wood lousewort's first find in Latvia. A deposit in Kurzeme, Rucava between Visminas and Zirnāji Vizuļi houses along the mountain, in a dry place. [Attēls no LU Muzeja kolekcijas Herbarium Latvicum (RIG II); (BOT1371)]