Article

Reproduction of Varroa destructor in South African honey bees: Does cell space influence Varroa male survivorship?

Apidologie (Impact Factor: 1.54). 01/2002; 33(1). DOI: 10.1051/apido:2001007

ABSTRACT The ability of Varroa destructor to reproduce in the African honey bee Apis mellifera scutellata was studied. In addition, the effects of space within the brood cell and short brood developmental time on mite reproduction, was investigated using A. m. scutellata cells parasitised by a A. m. capensis worker pseudo-clone. In A. m. scutellata worker cells Varroa produced 0.9 fertilised females per mother mite which is the same as found in susceptible European honey bees, but greater than the 0.4 produced in cells containing the pseudo-clone. Low mite reproductive success in cells containing pseudo-clone was mainly as a result of increased mite mortality. This was caused by male protonymphs and some mothers becoming trapped in the upper part of the cell due to the pseudo-clone being 8% larger than their host and not due to their short developmental time. Therefore, mite populations in South African A. m. scutellata and A. m. capensis honey bees are expected to increase to levels observed in Europe and USA.

Download full-text

Full-text

Available from: Per Kryger, Aug 19, 2015
0 Followers
 · 
236 Views
  • Source
    • "However, due to offspring mortality, the estimated number of female offspring reaching maturity is only 1.45 per cell. Many claims have been made about the potential benefit of using small-cell comb (Message and Gonçalves, 1995; Martin and Kryger, 2002; Piccirillo and de Jong, 2003) to reduce the space inside the cell, thus impeding movement of the mites and causing an increase in Article published by EDP Sciences mortality of mother mites and offspring, both male and female. However, the scientific evaluation of them has been limited. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The varroa mite (Varroa destructor) is an ectoparasite of the western honeybee Apis mellifera that reproduces in the brood cells. The mite will generally kill colonies unless treatment is given, and this almost universally involves the use of chemicals. This study was undertaken to examine the effect of small cell size on the reproductive success of the mite, as a method of non-chemical control in the Northern European honeybee Apis mellifera mellifera. Test colonies with alternating small and standard cell size brood combs were sampled over a three-month period and the population biology of the mites evaluated. To ensure high varroa infestation levels, all colonies were infested with mites from a host colony prior to commencement. A total of 2229 sealed cells were opened and the varroa mite families recorded. While small-sized cells were more likely to be infested than the standard cells, mite intensity and abundance were similar in both cell sizes. Consequently, there is no evidence that small-cell foundation would help to contain the growth of the mite population in honeybee colonies and hence its use as a control method would not be proposed.
    Apidologie 09/2010; 41(5):522-530. DOI:10.1051/apido/2010003 · 1.54 Impact Factor
  • Source
    • "However, several investigators support the hypothesis that the variation in the female reproductive capacity of the mite V. destructor on workers brood cells from different A. mellifera subspecies is the main factor for differences in the levels of infestation attained by the varroasis pest. In worker brood cells from African bees and their hybrids, the reproductive success of Varroa would be lower than with European bees; this would explain the low level of infestation caused by the mite V. destructor in Africanized bees in Brazil and other countries (Medina and Martin, 1999; Rosenkranz, 1999; Martin and Kryger, 2002; Calderon et al., 2003; Martin and Medina, 2004). However, studies on the genetic variability of the mite V. destructor showed that the virulence of varroasis is also related to different Varroa types (Kraus and Hunt, 1995; Anderson and Fuchs, 1998; De Guzman and Rinderer, 1999; Warrit et al., 2004; Solignac et al., 2003, 2005). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The mite Varroa destructor is an ectoparasite that is considered a major pest for beekeeping with European honey bees. However, Africanized bee colonies are less threatened by this ectoparasite, because infestation levels remain low in these bees. The low reproductive ability of female mites of the Japanese biotype (J), introduced to Brazil early in the 1970s was initially considered the main factor for the lack of virulence of this parasite on Africanized bees. In other regions of the world where the Korean (K) biotype of this mite was introduced, there have been serious problems with Varroa due to the high reproductive potential of the mite. However, a significant increase in the reproductive rate of females of Varroa in Brazil has been recently demonstrated; the cause could be a change in the type of Varroa in the bee colonies. We evaluated the prevalence of haplotypes J and K in mite samples collected from the State of Santa Catarina and from the island of Fernando de Noronha in the State of Pernambuco. The analysis of the mitochondrial genome (PCR + RFLP) revealed haplotype K in all samples from Santa Catarina and haplotype J in all samples from Fernando de Noronha. The analysis of microsatellites (nuclear genome) in bees from Fernando de Noronha showed only the specific alleles of haplotype J, while in bees from Santa Catarina, these alleles were found in only 2.8% of the samples. The high frequency of individuals with Korean genetic material is probably to the reason for the current high reproductive capacity of the mite V. destructor recorded in Santa Catarina.
    Genetics and molecular research: GMR 02/2009; 8(3):990-7. DOI:10.4238/vol8-3gmr567 · 0.85 Impact Factor
  • Source
    • "This implies that the threat to a colony can still be quantified by the number of mites with virulent mtDNA. While the genetics of an A. mellifera colony have a strong bearing on rates of V. destructor mortality (Ruttner and Hänel, 1992) and reproductive success in brood cells (Harris and Harbo, 2000; Martin and Kryger, 2002 ), there is no evidence of significant differences in these rates between the Japan and Korea haplotypes. Hence, fecundity and mortality were assumed to be the same for both the benign and virulent haplotypes. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The two haplotypes of Varroa destructor that have been identified as parasites of the Western honeybee (Apis mellifera L.) show disparate levels of virulence towards honeybee colonies. The Korea haplotype has been associated with severe colony mortality, whereas untreated colonies of European A. mellifera have survived long-term infestation by the Japan haplotype. The possible existence of a benign haplotype of V. destructor raises the prospect that it be used to "inoculate" colonies to provide biocontrol of the virulent haplotype. The feasibility of such a strategy was investigated using a mathematical model. Competition for resources during reproduction is known to reduce varroa mites' reproduction rates as their infestation levels increase. Results from modelling suggested this density-dependent effect is sufficient for an established benign population to prevent the virulent population reaching destructive levels if a colony is subject to sporadic influxes of virulent mites. A colony faced with a continuous influx of mites could be protected if the proportion of virulent mites in the influx were below a threshold level (dependent on length of breeding season and intensity of influx). This condition might be achieved by "inoculating" neighbouring apiaries and controlling feral colonies in the vicinity. Decreased brood cell invasion rate by the benign haplotype decreased the threshold level. Any reproductive isolation between the benign and virulent haplotypes would cause further reproductive suppression, driving sporadic influxes of the virulent haplotype to extinction and conferring greater tolerance to a colony faced with a virulent influx. Increased colony resistance to varroa in the model was synergistic with the inoculation of colonies in the absence of reproductive isolation, but potentially antagonistic in its presence—although not to an extent that would preclude their joint use.
    New Zealand Journal of Ecology 01/2006; 30(1). · 1.09 Impact Factor
Show more