Varroa sensitive hygiene

About: Varroa sensitive hygiene is a research topic. Over the lifetime, 714 publications have been published within this topic receiving 24928 citations. The topic is also known as: VSH.

Elucidating the mechanisms underlying the beneficial health effects of dietary pollen on honey bees ( Apis mellifera ) infested by Varroa mite ectoparasites

Abstract: Parasites and pathogens of the honey bee (Apis mellifera) are key factors underlying colony losses, which are threatening the beekeeping industry and agriculture as a whole. To control the spread and development of pathogen infections within the colony, honey bees use plant resins with antibiotic activity, but little is known about the properties of other substances, that are mainly used as a foodstuff, for controlling possible diseases both at the individual and colony level. In this study, we tested the hypothesis that pollen is beneficial for honey bees challenged with the parasitic mite Varroa destructor associated to the Deformed Wing Virus. First, we studied the effects of pollen on the survival of infested bees, under laboratory and field conditions, and observed that a pollen rich diet can compensate the deleterious effects of mite parasitization. Subsequently, we characterized the pollen compounds responsible for the observed positive effects. Finally, based on the results of a transcriptomic analysis of parasitized bees fed with pollen or not, we developed a comprehensive framework for interpreting the observed effects of pollen on honey bee health, which incorporates the possible effects on cuticle integrity, energetic metabolism and immune response.

High Humidity in the Honey Bee (Apis mellifera L.) Brood Nest Limits Reproduction of the Parasitic Mite Varroa jacobsoni Oud.

Abstract: Factors influencing reproduction of the parasitic mite Varroa jacobsoni have become a central theme of honey bee pathology. In large parts of the world the mite has made it impossible for colonies of the honey bee Apis mellifera to survive if no measures of treatment are applied [1]. Originally a parasite of the Eastern honey bee A. cerana, the mite was detected in colonies of A. mellifera only less than 4 decades ago [2]. A. cerana colonies are not damaged by V. jacobsoni because several factors prevent the build-up of a large mite population [3]. The most important factor is that in colonies of A. cerana the parasite, which can reproduce only in capped brood cells, reproduces exclusively in drone brood cells while in colonies of A. mellifera it reproduces in worker brood cells as well [4]. In cold, temperate, and Mediterranean climates the mite population grows exponentially until the colony collapses, due mainly to a high percentage of bees damaged by V. jacobsoni during their pupal development [5].

Invasion of Varroa destructor mites into mite-free honey bee colonies under the controlled conditions of a military training area

Abstract: SummaryThe honey bee mite Varroa destructor can be spread between colonies by vertical transmission, particularly when heavily infested colonies are robbed by foraging bees from neighbouring hives. We quantified the invasion of V. destructor into mite free colonies on a military training area not accessible to other beekeepers. Ten “mite receiver colonies” continuously treated against V. destructor were placed at distances of one to 1.5 km from four heavily infested “mite donor colonies”. Over a two month period from August to October, the population of bees, brood, and V. destructor in the donor colonies were estimated at three week intervals and the invasion of V. destructor into the receiver colonies was recorded every 7–12 days. During the experimental period, between 85 and 444 mites per colony were introduced into the receiver colonies. There were no significant differences in the invasion rates in relation to the distance between donor and receiver colonies. In total, 2,029 mites were found in the ...

Invasion of Varroa jacobsoni into honey bee brood cells: a matter of chance or choice?

Abstract: SUMMARYInvasion of Varroa jacobsoni into honey bee (Apis mellifera) brood cells was studied in three initially mite-free colonies. Frames with emerging worker brood, heavily infested with mites, were introduced into each colony and removed the next day. During the experiments ample worker brood was available for the mites to invade. Invasions into brood cells started immediately after the introduction of the mite-infested combs, showing that mites do not necessarily have to have a period on adult bees before invading a cell. However, as most mites stayed on the bees for several days or even several weeks, the average rate of invasion was rather low. In addition, replicate experiments in the three colonies showed much variation: 50% of the mites invaded brood cells within 2.0 days in the first replicate, within 8.3 days in the second replicate and within 4.3 days in the third replicate. Possible causes for the low and variable invasion rates are discussed.

Varying congruence of hygienic responses to Varroa destructor and freeze-killed brood among different types of honeybees

Abstract: Honeybees, Apis mellifera, selected for the hygienic removal of freeze-killed brood (FKB), resist several microbial diseases and have some resistance to Varroa destructor. Bees with Varroa-sensitive hygiene (VSH) have good resistance to V. destructor. We determined whether the response to FKB could be used to select for VSH by measuring the responses of different bees (VSH, FKB-selected, F1 VSH, and unselected control) to combs with FKB and combs with mite-infested brood. All bee types completely removed much FKB (77–88 %) within 24 h. The removal of mite-infested brood after 1 week was much more variable among bee types (VSH, 66 %; F1 VSH, 51 %; FKB hygienic, 14 %; control, 3 %). There was some relationship between 24-h manipulation of FKB cells (i.e., cell contents at least partially removed) and the removal of mite-infested brood, but this appears to have little practical relevance because of a large inherent variation.