Showing papers on "Varroa sensitive hygiene published in 1997"
TL;DR: This study showed that resistance to varroa mites is present in the honey bee population in the United States, nonreproduction of mites was highly correlated with the growth of a mite population, and nonreproducing mites may be a valuable characteristic for selecting bees for resistance tovarroamites.
Abstract: The purposes of this study were to select honey bees, Apis Mellifera L., for resistance to varroa mites, Varroa jacobsoni Oudemans, and to find a probable cause for this resistance. As a genetic source, we assembled 8 colonies that we thought had potential for resistance to varroa. Queens and drones were propagated from this group to produce 43 instrumentally inseminated queens, each queen mated to only 1 drone. Colonies from 27 of these queens were tested in Louisiana and 16 were tested in Michigan. Each colony in the Louisiana test began with 986 ± 13 g (mean ± SD) of bees and =290 mites; Michigan colonies began with 3,212 ± 171 bees and =51 mites. The populations of mites and bees were measured 10 wk later. Three of the 43 colonies had fewer mites at the end of the test than at the beginning. During the experiment, we evaluated each colony for grooming behavior, hygienic behavior, the duration of the postcapping period, and the frequency of nonreproducing mites in brood cells. of these 4 characteristics, only nonreproduction of mites was highly related to a change in the mite population. The duration of the postcapping period was marginally related, and the other 2 characteristics were apparently unrelated to the growth of the mite population. This study showed that resistance to varroa mites is present in the honey bee population in the United States, nonreproduction of mites was highly correlated with the growth of a mite population, and nonreproduction of mites may be a valuable characteristic for selecting bees for resistance to varroa mites.
92 citations
TL;DR: By December, colony bee populations were optimum in August-treated apiaries, and the data suggest that late-season acaricide treatments in firs...
Abstract: SUMMARYWe set up 72 colonies of honey bees (Apis mellifera) in the piedmont region of Georgia and South Carolina, USA (2 states × 6 apiaries per state × 6 colonies per apiary) in April 1995. Colonies were individually housed in single-chamber Langstroth hive bodies and one honey super, started with standard mail-order 0.9 kg (2lb) packages of bees containing small incipient populations of the parasitic mite Varroa jacobsoni, and managed optimally as for honey production. Within each state, each apiary was assigned one of the following treatments: (1) treatment with Apistan acaricide in June, (2) treatment in August, (3) treatment in October, or (4) no treatment By December, colony bee populations were optimum in August-treated apiaries. Month of treatment did not affect bee body weight. There were treatment by state interactions for number of sealed brood cells, colony mite populations, and percentage of brood cells with disease-like symptoms. Our data suggest that late-season acaricide treatments in firs...
72 citations
TL;DR: A new experimental method is described for studying the number of reproductive cycles in the mites' biology in order to resolve the problem of rapid build up of mite populations in Apis mellifera colonies.
Abstract: SUMMARYDue to the low fecundity of Varroa jacobsoni, it is presently not possible to explain satisfactorily the observed rapid build up of mite populations in Apis mellifera colonies. The number of reproductive cycles, i.e. the number of times a mite enters brood cells to reproduce, has been suggested to be the key to this problem. Despite several studies on this aspect, large discrepancies in the published data remain. This paper describes a new experimental method for studying this aspect of the mites' biology in order to resolve this question. Colonies containing only worker bee brood were manipulated so they had discrete brood cycles. Colonies were kept in a mite-free area and infested with a known number of mites at the start of the study. To estimate the average number of reproductive cycles performed, the observed growth in the mite populations was compared with the theoretical growth of mite populations which performed different numbers of reproductive cycles, but with conditions otherwise similar...
59 citations
TL;DR: Factors influencing reproduction of the parasitic mite Varroa jacobsoni have become a central theme of honey bee pathology and in cold, temperate, and Mediterranean climates the mite population grows exponentially until the colony collapses.
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].
44 citations
TL;DR: The distribution of Varroa jacobsoni on clustered, overwintering workers of Apis mellifera was investigated and results suggest that the mites suffer a lower overwinter mortality than the bees and are capable of transferring to a new host either before the original host dies or before it falls to the floor of the hive.
Abstract: The distribution of Varroa jacobsoni on clustered, overwintering workers of Apis mellifera was investigated. The majority of mites were found between the 3rd and 4th ventro-lateral tergites of the abdomen with a significant preference for the left side of the host. This position would enable the mites to place their mouthparts in close proximity to the central portion of the bees' ventriculus. This may allow the mites access to nutrients at higher concentrations than would occur elsewhere in the haemolymph. At the start of winter, most infested bees carried only a single mite but towards the end increasing numbers of bees carried 2 or more mites. There was also an increase in the mite: bee ratio and more mobile mites (i.e. those moving about on the bees) were recorded. These results suggest that the mites suffer a lower overwinter mortality than the bees and are capable of transferring to a new host either before the original host dies or before it falls to the floor of the hive. This will have consequences for the transfer of diseases by Varroa within the hive.
29 citations
TL;DR: In Vietnam, various biotechnical methods are used by professional beekeepers to control Varroa jacobsoni and Tropilaelaps clareae and the methods suffice to successfully control both mite species without the use of chemicals.
Abstract: In Vietnam, various biotechnical methods are used by professional beekeepers to control Varroa jacobsoni and Tropilaelaps clareae. For control of tropilaelaps, a broodless period has to be created. Varroa is controlled by trapping methods. The methods suffice to successfully control both mite species without the use of chemicals.
8 citations
Journal Article•
TL;DR: Fortunately, pesticides and other agricultural chemicals are not incorporated into the honey and foraging bees return to the hive with contaminated nectar or pollen, and natural provisions that protect the honey from contamination.
Abstract: Fortunately, pesticides and other agricultural chemicals are not incorporated into the honey. Bees that collect pesticide-contaminated nectar or pollen usually die away from the hive. If foraging bees return to the hive with contaminated nectar or pollen, there are natural provisions that protect the honey from contamination. Bees will usually leave the hive if they become poisoned. Pollen is stored in combs for feeding the brood (young bees). Contaminated pollen may kill the nurse bees and the brood.
7 citations