Impact of Varroa destructor on honeybee (Apis mellifera scutellata) colony development in South Africa (original) (raw)
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Acta Scientiarum. Animal Sciences, 2015
This study evaluated the level of invasion of Varroa mite into worker brood cells, the infestation rate on adult worker honeybees, total and effective reproduction rates of the mite in Africanized honeybee colonies under royal jelly or honey production. Invasion and infestation rates were not statistically different between honeybee colonies producing honey or royal jelly and the averages for these parameters were 5.79 and 8.54%, respectively. Colonies producing honey presented a higher (p < 0.05) total and effective reproduction of Varroa than colonies producing royal jelly. There was a negative correlation between levels of invasion and infestation with minimum external temperature, relative humidity and rainfall. The variables month and season influenced the development of the mite, but rates were low and within the range normally found in Brazil for Africanized honeybee colonies, which confirm the greater resistance of these honeybees to Varroa destructor than European honeybees.
Possible host-parasite adaptations in honey bees infested by Varroa destructor mites
Apidologie, 2007
We investigated Varroa destructor mite population growth in a line of honey bee (Apis mellifera) colonies hat have survived mite infestation for seven years without treatment (Bond colonies), and in a line of colonies that had been treated to control the mites (Controls). We investigated if the source of mites affected mite population growth. The results showed that the overall mite population growth rate was reduced by 82% in Bond colonies compared to Control colonies, irrespective of the mite source (mites from Bond or Control colonies). Two traits may partly explain the difference seen in mite population growth. First, Bond colonies produced less worker and drone brood compared to Control colonies. Second, Control colonies had a larger proportion of the mites in the sealed brood compared to Bond colonies. Reduced brood production and traits leading to differences in mite distribution could be interpreted as adaptive responses to mite pressure, although a causal relationship was not demonstrated.
Controlled Infestation of Honeybee Colonies with Varroa Destructor Females
Journal of Apicultural Science
The development of female Varroa destructor mites in the bee colonies was examined in the apiculture season through a developed research system in which bee colonies were experimentally infested with fifty V. destructor females. Differences in infestation rates were observed between the control group (C) and the infested group (E). The average number of female mites per colony was determined at 513 in group E and 261.6 in group C. Natural daily mortality reached 0.16 mites in group E and 0.09 mites in group C. In group E, the number of V. destructors increased 7.96 to 13.32-fold, subject to colony. The size of V. destructor populations increased at a higher rate in group E than in group C (F= 12.39, P= 0.047). At the end of the experiment, the percentage of infested honey bee workers was determined at 0.97% in group E and 0.46% in group C. The results of this study confirmed that V. destructor mites continue to proliferate rapidly in honey bee colonies, and that the population growt...
Population Dynamics of Varroa Mites and Bee Lice in Honey Bees Colonies
2019
This study was designed to evaluate the population dynamics of Varroa mites and bee lice in naturally infested honey bee colonies Apis mellifera Varroa destructor and Braula coeca infestation rate on both adult bees and sealed brood was estimated, in addition of the estimation of falling parasites trapped by using anti-varroa bottom boards. The results showed that mean infestation rate of V. destructor on adults and brood was 2 % on January, increased rapidly on June to reach the maximum of 40% , then decreased again to the season minimum rate in Dec 2014. The infestation rate of B. coeca began to increase rapidly in May, reaching the season’s maximum rate of 2.1 %, for A. mellifera in December of 2014. We conclude both of the honey bee parasites were found in the apiary with the most common parasite being the Varroa mite. In spite of hosting few pathogens, yet most parasites, A. m. colonies appeared to
This study evaluated the level of invasion of Varroa mite into worker brood cells, the infestation rate on adult worker honeybees, total and effective reproduction rates of the mite in Africanized honeybee colonies under royal jelly or honey production. Invasion and infestation rates were not statistically different between honeybee colonies producing honey or royal jelly and the averages for these parameters were 5.79 and 8.54%, respectively. Colonies producing honey presented a higher (p < 0.05) total and effective reproduction of Varroa than colonies producing royal jelly. There was a negative correlation between levels of invasion and infestation with minimum external temperature, relative humidity and rainfall. The variables month and season influenced the development of the mite, but rates were low and within the range normally found in Brazil for Africanized honeybee colonies, which confirm the greater resistance of these honeybees to Varroa destructor than European honeybees.
Experimental and Applied Acarology, 2016
Varroa (Varroa destuctor Anderson and Trueman) populations in honey bee (Apis mellifera L.) colonies might be kept at low levels by well-timed miticide applications. HopGuard Ò (HG) that contains beta plant acids as the active ingredient was used to reduce mite populations. Schedules for applications of the miticide that could maintain low mite levels were tested in hives started from either package bees or splits of larger colonies. The schedules were developed based on defined parameters for efficacy of the miticide and predictions of varroa population growth generated from a mathematical model of honey bee colony-varroa population dynamics. Colonies started from package bees and treated with HG in the package only or with subsequent HG treatments in the summer had 1.2-2.
Controlled Infestation of Honeybee Colonies with Varroa Destructor Females
Journal of Apicultural Science, 2019
The development of female Varroa destructor mites in the bee colonies was examined in the apiculture season through a developed research system in which bee colonies were experimentally infested with fifty V. destructor females. Differences in infestation rates were observed between the control group (C) and the infested group (E). The average number of female mites per colony was determined at 513 in group E and 261.6 in group C. Natural daily mortality reached 0.16 mites in group E and 0.09 mites in group C. In group E, the number of V. destructors increased 7.96 to 13.32-fold, subject to colony. The size of V. destructor populations increased at a higher rate in group E than in group C (F= 12.39, P= 0.047). At the end of the experiment, the percentage of infested honey bee workers was determined at 0.97% in group E and 0.46% in group C. The results of this study confirmed that V. destructor mites continue to proliferate rapidly in honey bee colonies, and that the population growth rate in bee colonies and apiaries has to be closely monitored due to growing levels of resistance to acaricides.
Saudi Journal of Biological Sciences, 2016
Varroa mite is the most destructive pest to bee colonies worldwide. In Saudi Arabia, preliminary data indicated high infestation levels in the exotic honeybee colonies; such as Apis mellifera carnica and Apis mellifera ligustica, compared to native honeybee subspecies Apis mellifera jemenitica, which may imply higher tolerance to Varroasis. In this study, fertility and reproductive rate of Varroa mite, Varroa destructor, in capped brood cells of the native honeybee subspecies were investigated and compared with an exotic honeybee subspecies, A. m. carnica. Mite fertility was almost alike (87.5% and 89.4%) in the native and craniolan colonies respectively. Similarly, results did not show significant differences in reproduction rate between both subspecies (F = 0.66, Pr > F = 0.42). Number of adult Varroa daughters per fertile mother mite was 2.0 and 2.1 for native and craniolan honeybee subspecies respectively. This may indicate that mechanisms of keeping low infestation rates in the native honeybee colonies are not associated with Varroa reproduction. Therefore, potential factors of keeping lower Varroa infestation rates in native honey bee subspecies should be further investigated.
Varroa mites and honey bee health: can Varroa explain part of the colony losses
Since 2006, disastrous colony losses have been reported in Europe and North America. The causes of the losses were not readily apparent and have been attributed to overwintering mortalities and to a new phenomenon called Colony Collapse Disorder. Most scientists agree that there is no single explanation for the extensive colony losses but that interactions between different stresses are involved. As the presence of Varroa in each colony places an important pressure on bee health, we here address the question of how Varroa contributes to the recent surge in honey bee colony losses.
Parasitology, 2015
SUMMARYVarroa destructoris considered the most damaging parasite affecting honeybees (Apis melliferaL.). However, some honeybee populations such as the savannah honeybee (Apis mellifera scutellata) can survive mite infestation without treatment. It is unclear if survival is due to resistance mechanisms decreasing parasite reproduction or to tolerance mechanisms decreasing the detrimental effects of mites on the host. This study investigates both aspects by quantifying the reproductive output ofV. destructorand its physiological costs at the individual host level. Costs measured were not consistently lower when compared with susceptible honeybee populations, indicating a lack of tolerance. In contrast, reproduction ofV. destructormites was distinctly lower than in susceptible populations. There was higher proportion of infertile individuals and the reproductive success of fertile mites was lower than measured to date, even in surviving populations. Our results suggest that survival o...