Search results for "Varroa"
showing 10 items of 13 documents
Rietumu medusbites (Apis mellifera L.) būtiskāko parazītisko mikrosporīdiju (Nosema spp.) un ērču (Varroa destructor) izplatību un sastopamību ietekm…
2019
Medusbišu, tāpat kā citu apputeksnētāju, skaita samazināšanās Eiropā un pasaulē kopumā saistāma t.sk. ar parazitārām slimībām. Šī pētījuma mērķis ir izpētīt Rietumu medusbišu (Apis mellifera L.) būtiskāko parazītu (Nosema spp., Varroa destructor) izplatību un sastopamību ietekmējošos faktorus Latvijā. Laikā no 2012.-2013. gadam ievākti bišu paraugi no 274 dravām, lai noteiktu to invāzijas slimību sastopamību Latvijas teritorijā. Pētījumā konstatēta Nosema spp. prevalence 49,5% un vidējā intensitāte 8,5x105 sporas uz vienu biti. Savukārt V. destructor prevalence bija 52,3% un vidējā intensitāte 3,0 ērces uz 100 bitēm. Būtiskākie parazītu sastopamību ietekmējošie faktori bitēs Latvijā bijā se…
Influence of brood temperature and hygrometry variations on the development of the honey bee ectoparasite Varroa jacobsoni (Mesostigmata : Varroidae)
1990
The influence of different temperatures (from 26 to 39.5°C) and relative humidities (40 and 70%) on the development of Varma jacobsoni (Oudemans) was studied by placing newly capped and parasitized worker bee broods into thermostatically controlled chambers. In one set of experiments the temperature was kept constant, and in the second set, the parasitized worker broods were placed at a temperature of 40,41, or 42°C for a time varying from 0 to 24 h and then returned to 32.5°C. The optimal temperature for development of the mites was between 32.5 and 33.4°C, which corresponds to the brood temperature of Apis mellifera L. Above 36.5°C, reproduction of varroa females was significantly reduced…
The Odorant-Binding Proteins of the Spider Mite Tetranychus urticae
2021
Spider mites are one of the major agricultural pests, feeding on a large variety of plants. As a contribution to understanding chemical communication in these arthropods, we have characterized a recently discovered class of odorant-binding proteins (OBPs) in Tetranychus urticae. As in other species of Chelicerata, the four OBPs of T. urticae contain six conserved cysteines paired in a pattern (C1–C6, C2–C3, C4–C5) differing from that of insect counterparts (C1–C3, C2–C5, C4–C6). Proteomic analysis uncovered a second family of OBPs, including twelve members that are likely to be unique to T. urticae. A three-dimensional model of TurtOBP1, built on the recent X-ray structure of Varroa destruc…
Bacterial communities associated with the ectoparasitic mites Varroa destructor and Tropilaelaps mercedesae of the honey bee (Apis mellifera).
2017
Varroa and Tropilaelaps mites have been reported as serious ectoparasites of the honey bee (Apis mellifera). In this study, bacterial communities associated with Varroa destructor and Tropilaelaps mercedesae from northern Thailand were determined, using both culture-dependent and culture-independent approaches. Adult female mites were collected from apiaries in Chiang Mai and Lampang provinces. Culturable bacteria were isolated from individual mites. On average, we observed approximately 1340 and 1140 CFU/mite in Varroa and Tropilaelaps, respectively. All isolates were assigned to the genus Enterococcus. Six samples of genomic DNA from 30-50 mites were extracted and subjected to pyrosequenc…
Pyrrethroid resistance in Varroa destructor: Investigating the role of mutations in the voltage-gated sodium channel
2022
Entre les majors amenaces de l'apicultura contemporània es troba el parasitisme de Varroa destructor, Anderson & Trueman (Acari: Varroidae). Aquest àcar ectoparàsit altament especialitzat s'alimenta directament de les pupes i els adults de l'abella mel·lífera europea, Apis mellifera L. (Hymenoptera: Apidae), la qual cosa debilita greument a les abelles i les indueix una immunosupressió que desemboca en brots d'infeccions preexistents o vectorizades pels àcars que comprometen la viabilitat de les colònies. El control dels àcars V. destructor es un problema agreujat pel limitat número de tractaments de control disponibles i l'evolució de la resistència a aquests en les poblacions d'àcars. Enc…
Mutations associated with pyrethroid resistance in Varroa mite, a parasite of honey bees, are widespread across the United States.
2021
BACKGROUND Managed honey bees are key pollinators of many crops and play an essential role in the United States food production. For more than ten years, beekeepers in the United States have been reporting high rates of colony losses. One of the drivers of these losses is the parasitic mite Varroa destructor. Maintaining healthy honey bee colonies in the United States is dependent on a successful control of this mite. The pyrethroid tau-fluvalinate (Apistan®) was among the first synthetic varroacides registered in the United States. With over 20 years of use, mites resistant to Apistan® have emerged, and so it is unsurprising that treatment failures have been reported. Resistance to tau-flu…
Mutations associated with pyrethroid resistance in Varroa mites, a parasite of honey bees, are widespread across the USA
2020
ABSTRACTBACKGROUNDManaged honey bees are key pollinators of many crops and play an essential role in the United States food production. For more than 10 years, beekeepers in the US have been reporting high rate of colony losses. One of the drivers of this colony loss is the parasitic mite Varroa destructor. Preserving healthy honey bee colonies in the US is dependent on a successful control of this mite. The pyrethroid tau-fluvalinate (Apistan®) was among the first synthetic varroacide registered in the US. With over 20 years of use, population of mites resistant to Apistan® have emerged, and so it is unsurprising that treatment failures have been reported. Resistance in US mite populations…
Novel mutations in the voltage-gated sodium channel of pyrethroid-resistant Varroa destructor populations from the Southeastern USA
2016
The parasitic mite Varroa destructor has a significant worldwide impact on bee colony health. In the absence of control measures, parasitized colonies invariably collapse within 3 years. The synthetic pyrethroids tau-fluvalinate and flumethrin have proven very effective at managing this mite within apiaries, but intensive control programs based mainly on one active ingredient have led to many reports of pyrethroid resistance. In Europe, a modification of leucine to valine at position 925 (L925V) of the V. destructor voltage-gated sodium channel was correlated with resistance, the mutation being found at high frequency exclusively in hives with a recent history of pyrethroid treatment. Here,…
Integrative taxonomy demonstrates the unexpected synonymy between two predatory mite species: Cydnodromus idaeus and C. picanus (Acari: Phytoseiidae)
2011
Contact: tixier@supagro.inra.fr; Species of the mite family Phytoseiidae are well known as predators of mite pests all over the world. Their identification is thus of great interest for biological control. The specimens examined in this study belong to the species Cydnodromus idaeus (described from Brazil) and C. picanus (described from Chile). They were collected together on the same plant in Argentina. These species are mainly differentiated by the presence/absence of the dorsal solenostomes (gland openings) gd2. Some morphometric differences were observed between the Argentinian specimens and the type material of C. idaeus and C. picanus; however, they were not sufficient to support a sp…
Honey Bee Suppresses the Parasitic Mite Vitellogenin by Antimicrobial Peptide
2020
AbstractThe negative effects of honey bee parasitic mites and deformed wing virus (DWV) on honey bee and colony health have been well characterized. However, the relationship between DWV and mites, particularly viral replication inside the mites, remains unclear. Furthermore, the physiological outcomes of honey bee immune responses stimulated by DWV and the mite to the host (honey bee) and perhaps the pathogen/parasite (DWV/mite) are not yet understood. To answer these questions, we studied the tripartite interactions between the honey bee,Tropilaelaps mercedesae, and DWV as the model.T. mercedesaefunctioned as a vector for DWV without supporting active viral replication. Thus, DWV negligib…