Showing papers on "Varroa sensitive hygiene published in 2003"
TL;DR: The data suggested that optimum mite control could be achieved when no brood is being produced, or when brood production is low, such as in the early spring or late fall, and that the fungus was infecting and killing the mites.
Abstract: The potential for Metarhizium anisopliae (Metschinkoff) to control the parasitic mite, Varroa destructor (Anderson and Trueman) in honey bee colonies was evaluated in field trials against the miticide, tau-fluvalinate (Apistan). Peak mortality of V. destructor occurred 3–4 d after the conidia were applied; however, the mites were still infected 42 d posttreatments. Two application methods were tested: dusts and strips coated with the fungal conidia, and both methods resulted in successful control of mite populations. The fungal treatments were as effective as the Apistan, at the end of the 42-d period of the experiment. The data suggested that optimum mite control could be achieved when no brood is being produced, or when brood production is low, such as in the early spring or late fall. M. anisopliae was harmless to the honey bees (adult bees, or brood) and colony development was not affected. Mite mortality was highly correlated with mycosis in dead mites collected from sticky traps, indicating that the fungus was infecting and killing the mites. Because workers and drones drift between hives, the adult bees were able to spread the fungus between honey bee colonies in the apiary, a situation that could be beneficial to beekeepers.
91 citations
TL;DR: The first exact data on individual drone weight loss, especially from the red eyed pupal stage onwards, is presented, where the resulting reduction in weight of adult drones was related to the number of female mites that had invaded a brood cell.
Abstract: Colony losses caused by varroatosis in the western hive bee, Apis mellifera, are mainly due to worker bee injury by Varroa destructor mites during preimaginal development. These effects have been examined repeatedly; however, little is known about effects on drones. Here we present the first exact data on individual drone weight loss, especially from the red eyed pupal stage onwards. The resulting reduction in weight of adult drones was related to the number of female mites (up to 20) that had invaded a brood cell. Weight loss was significant even if only one female mite was present. From several of the heavily infested brood cells adult mini-drones emerged. Varroosis / multiple drone brood infestation / preimaginal weight loss / male fitness / Apis mellifera / Varroa destructor
88 citations
TL;DR: Surprisingly, the mite infestation levels of swarms in the late fall were not significantly different from those of swarming colonies the same year, indicating that swarm survival may be almost as much affected by V. destructor, as intact, swarmed colonies.
Abstract: In a honey bee population of 150 colonies, the development of an introduced Varroa destructor mite population was monitored in swarming and non-swarming colonies for two years in a Nordic climate. The results demonstrated a reduced mite population as a result of swarming only for the first swarm season studied. In the second swarm season, there were much higher mite levels (based on debris counts of mites) and fewer colonies swarmed, but there was no significant difference in infestation levels of adult bees in the fall between swarming and non-swarming colonies. This result was interpreted as an effect of host-parasite interactions, where the detrimental influence from the infestation prohibited growth (and swarming) in some colonies, but allowed better mite reproduction opportunities (and swarming) in others. Surprisingly, the mite infestation levels of swarms in the late fall were not significantly different from those of swarming colonies the same year, indicating that swarm survival may be almost as much affected by V. destructor, as intact, swarming colonies. No horizontal mite transfer through robbing was observed. The results suggest that, horizontal mite transfer may not be as important in a Nordic climate where many bee colonies die over winter along with their mites, as it is in warmer climates. Varroa destructor / Apis mellifera / swarming / survival / nordic climate / population dynamics
85 citations
01 Jan 2003
TL;DR: The aim of this article is to provide more background information on the different steps of this alternative treatment strategy, developed over the past 15 years.
Abstract: The bee parasite Varroa destructor has developed resistance against traditional varroacides in many regions of Europe . Of course, there are substitutes, such as organic acids and components of essential oils. However, these are effective only, if applied in the frame of a control strategy. The aim of this article is to provide more background information on the different steps of this alternative treatment strategy, developed over the past 15 years.
55 citations
TL;DR: It is proposed as complimentary measures the removal of drone brood or the division of young colonies in spring to retard the development of varroa populations, and thus reduce the pressure of infestation.
Abstract: Some acaricides used as alternative controls against Varroa destructor, for example formic acid or essential oils, are not always sufficiently effective. We propose as complimentary measures the removal of drone brood or the division of young colonies in spring. These interventions serve to retard the development of varroa populations, and thus reduce the pressure of infestation. They have the advantage of being able to be carried out at the height of the beekeeping season when recourse to chemotherapy would present serious risks of contamination of the honey harvest.
41 citations
Journal Article•
TL;DR: The small width comb cells produced by Africanized honey bees may have a role in the ability of these bees to tolerate infestations by Varroa destructor, furthermore it appears that natural-sized comb cells are superior to over- sized comb cells for disease resistance.
Abstract: Africanized honey bees (Apis mellifera, Hymenoptera: Apidae) in Brazil are tolerant of infestations with the exotic ectoparasitic mite, Varroa destructor (Mesostigmata: Varroidae), while the European honey bees used in apiculture throughout most of the world are severely affected. Africanized honey bees are normally kept in hives with both naturally built small width brood cells and with brood cells made from European-sized foundation, yet we know that comb cell size has an effect on varroa reproductive behavior. Three types (sizes) of brood combs were placed in each of six Africanized honey bee colonies: new (self-built) Africanized comb, new Italian comb (that the bees made from Italian-sized commercial foundation), and new Carniolan comb (built naturally by Carniolan bees). About 100 cells of each type were analyzed in each colony. The Africanized comb cells were significantly smaller in (inner) width (4.84 mm) than the European-sized comb cells (5.16 and 5.27 mm for Italian and Carniolan cells, respectively). The brood cell infestation rates (percentage cells infested) were significantly higher in the Carniolan-sized comb cells (19.3%) than in the Italian and Africanized cells (13.9 and 10.3%, respectively). The Carniolan-sized cells also had a significantly larger number of invading adult female mites per 100 brood cells (24.4) than did the Italian-sized cells (17.7) and the natural-sized Africanized worker brood cells (15.6). European-sized worker brood cells were always more infested than the Africanized worker brood cells in the same colony. There was a highly significant correlation (P<0.01) between cell width and the rate of infestation with varroa in four of the six colonies. The small width comb cells produced by Africanized honey bees may have a role in the ability of these bees to tolerate infestations by Varroa destructor, furthermore it appears that natural-sized comb cells are superior to over-sized comb cells for disease resistance.
40 citations
TL;DR: The data suggest that for unknown reasons tracheal mites appear to be very rare in Turkey, but not varroa, which has endemic rather than epidemic disease distribution properties.
Abstract: SUMMARYThis is the first extensive study of the incidence of varroa (Varroa destructor) and tracheal mites (Acarapis woodi) in Turkish honey bees (Apis mellifera). Samples were taken from 204 colonies in 39 apiaries spread over five regions of Turkey. Fifty bees from each colony were dissected in the laboratory and examined under stereo and compound microscopes using four different techniques to detect the presence of A. woodi. Presence of varroa was determined from samples of approximately 200 workers from each of the sampled colonies. Neither A. woodi nor other Acarapis spp. were found in any of the 10 200 bees examined. Conversely, varroa was found in 84 of the 204 colonies sampled. Varroa incidence per apiary was approximately Poisson distributed with a mean of 2.17 infested colonies per five sampled. The data suggest that for unknown reasons tracheal mites appear to be very rare in Turkey, but not varroa, which has endemic rather than epidemic disease distribution properties.
36 citations
TL;DR: The occurrence of adult bee mortality and the detection of these viruses in Africanized colonies in Costa Rica infested with V. destructor, should be considered as a cause of concern.
Abstract: Newly emerged bees with damaged wings, bees crawling in front of the hive and unusually severe adult bee mortality were observed in Africanized honey bee colonies in Costa Rica. A large proportion of the adult bee population in most of these colonies was infested with Varroa destructor. Adult bee samples were sent to the Department of Entomology, Penn state university, for virus analysis. This analysis showed the presence of deformed wing virus and Kashmir bee virus. The occurrence of adult bee mortality and the detection of these viruses in Africanized colonies in Costa Rica infested with V. destructor, should be considered as a cause of concern.
29 citations
TL;DR: It is concluded that honey bees can be successfully managed for greenhouse tomato pollination in both screened and unscreened greenhouses if the foraging force is maintained by replacing colonies every 3 wk.
Abstract: Although commercially reared colonies of bumble bees (Bombus sp.) are the primary pollinator world-wide for greenhouse tomatoes (Lycopersicon esculentum Mill.) previous research indicates that honey bees (Apis mellifera L.) might be a feasible alternative or supplement to bumble bee pollination. However, management methods for honey bee greenhouse tomato pollination scarcely have been explored. We 1) tested the effect of initial amounts of brood on colony population size and flight activity in screened greenhouses during the winter, and 2) compared foraging from colonies with brood used within screened and unscreened greenhouses during the summer. Brood rearing was maintained at low levels in both brood and no-brood colonies after 21 d during the winter, and emerging honey bees from both treatments had significantly lower weights than bees from outdoor colonies. Honey bee flight activity throughout the day and over the 21 d in the greenhouse was not influenced by initial brood level. In our summer experiment, brood production in screened greenhouses neared zero after 21 d but higher levels of brood were reared in unscreened greenhouses with access to outside forage. Flower visitation measured throughout the day and over the 21 d the colonies were in the greenhouse was not influenced by screening treatment. An economic analysis indicated that managing honey bees for greenhouse tomato pollination would be financially viable for both beekeepers and growers. We conclude that honey bees can be successfully managed for greenhouse tomato pollination in both screened and unscreened greenhouses if the foraging force is maintained by replacing colonies every 3 wk.
29 citations
TL;DR: The control of V. destructor in honey been colonies by management methods and organic and traditional methods of chemical control are discussed.
Abstract: Klaus Wallner from Universitat Hohenheim in Stuttgart, Germany and Ingemar Fries from the Swedish University of Agricultural Sciences in Uppsala, Sweden discuss the control of V. destructor in honey been colonies by management methods and organic and traditional methods of chemical control.
20 citations
TL;DR: It indicated that worm wood flowers, peppermint oil and clove oil treatments gave the best results in the control of Varroa mites but not significantly different than the control.
Abstract: The effect of several volatile plant oils, plant materials and fluvalinate (Apistan®) strips on the control of the mite Varroa destructor on honeybee (Apis mellifera L.) colonies was studied. The volatile oils were: clove, lavender, peppermint, sage, and thyme. The plant materials were: cumin fruits, eucalyptus leaves, and worm wood flowers. For each tested material, three treatment periods were carried out. Each period lasted for 24 days followed by eight days no-treatment. Within each treatment period, an average of three to six treatments were applied. Dead mites were counted one hour before and after each treatment. An increase in dead mites was recorded for the three treatment periods. It indicated that worm wood flowers, peppermint oil and clove oil treatments gave the best results in the control of Varroa mites but not significantly different than the control. The overall increase in the dead mites was 3.92, 3.62 and 3.34 fold, respectively.
TL;DR: The AHB population monitored in this study may be less tolerant to varroa than AHB populations in Brazil, and the number of fertile mites was higher than that reported in other studies for AHB in Brazil.
Abstract: SUMMARYFrom February to July 2001, the reproductive ability of Varroa destructor in artificially infested worker brood cells of Africanized honey bees (AHB) (Apis mellifera) and hybrids (HF1) of AHB X European honey bees was investigated in Costa Rica. No significant differences were found between AHB and HF1 in the percentage of fertile foundress mites (AHB = 69.8%, HF1 = 76.5%), the percentage of foundress mites that produced mature female offspring (AHB = 28%, HF1 = 25.4%), the mean number of offspring per foundress (AHB = 3.4, HF1 = 3.5) and the percentage of foundress mites that produced only immature stages (AHB = 17.3%, HF1 = 18.2%). Nevertheless, the percentage of foundress mites that did not reproduce at all tended to be greater in AHB than in HF1 colonies (AHB = 30.2%, HF1 = 23.5%; P = 0.06). In both groups of bees, the number of fertile mites was higher than that reported in other studies for AHB in Brazil (49–55%). Furthermore, the percentage of non-reproducing mites was greater than the perce...
TL;DR: The effects of varroa on drones, and the potential powerful role of male gamete selection in the breeding of mite-resistant bees are summarized.
Abstract: This article summarizes the effects of varroa on drones, and explores the potential powerful role of male gamete selection in the breeding of mite-resistant bees.
Journal Article•
TL;DR: Very few nematode species are honey bee parasites and there are no records of nematodes that live freely in bee colonies and attack the honey bees therein.
Abstract: Very few nematode species are honey bee parasites.16 There are no records of nematodes that live freely in bee colonies and attack the honey bees therein.17 Those that have been found in forager bees are usually nematodes of the Mermithidae family.15
TL;DR: It is anticipated that supplementing trap baits with guanine, the main component of mite excreta, may be useful as a control tactic and that the lack of a defense secretion makes V. destructor vulnerable and ideal for control by introducing a mite predator.
Abstract: The potential of pheromone-assisted techniques for management and control of Varroa, the behavior of conspecific mites (Varroa destructor) towards each other, and their corresponding extracts, were examined. Neither actual mites nor extracts prompted significant attraction responses or avoidance reactions that were indicative of aggregation-attachment, sex or alarm (= allomonal defense secretion) pheromone production. A mite- exposed filter paper disc covered with mite excreta, however, was highly attractive to mites and shows use of an assembly pheromone. This confirms involvement of the fecal accumulation in concentrating mites on brood cell walls between bloodmeals. Interestingly, formation of clusters at the fecal accumulation performs functional values of those pheromones that are absent. We anticipate that supplementing trap baits with guanine, the main component of mite excreta, may be useful as a control tactic. Alternatively, the lack of a defense secretion makes V. destructor vulnerable...
TL;DR: This study found that 86.75 and 93% of the mites were fertile in worker and drone cells, respectively, when including those mother mites that produced male only offspring, whereas excluding these offspring, the fertility decreased to 82 and 90% in workers and drones, respectively.
Abstract: Reproductive biology of the mite Varroa jacobsoni Oud. was studied under Michigan conditions in Apis mellifera L. colonies. A total of 353 sealed worker brood cells containing 697 mother mites and 192 sealed drone brood cells containing 498 mother mites were found in 959 sealed worker brood cells and 344 sealed drone brood cells that were examined. Number of offspring were calculated using two different methods, the first one included adult females that either did not produce offspring, or produced only male and dead offspring. While the second method included mother mites producing only live female offspring. It was found that the mean number of females offspring reaching maturity before the bee emerged in worker and drone cells containing a single mother mite are 1.41 and 2.47 offspring, respectively (First method). When the nonreproducing and male only reproducing females (second method) were excluded the mean number increased to 1.82 for workers and 2.69 for drones. In case of the infestation with more than one adult female, the average number of offspring remained 1.09 for workers and 1.87 for drones (First method). These increased to 1.26 and 2.03, respectively, when non-reproducing and male only reproducing mother mites were excluded (Second method. This study found that 86.75 and 93% of the mites were fertile in worker and drone cells, respectively, when including those mother mites that produced male only offspring. Whereas excluding these offspring, the fertility decreased to 82 and 90% in worker and drone cells, respectively. The results also showed that the percentage of non-reproducing females was 11 and 7% in worker and drone cells, respectively. While the mortality percentage of mother mites was recorded 2.29 and 2.7% in worker and drone brood cells, respectively.
01 Nov 2003
01 Jan 2003