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.

Africanized honey bees (Apis mellifera) have low infestation levels of the mite Varroa destructor in different ecological regions in Mexico.

Abstract: Honey bee (Apis mellifera) colonies of African and European descent were compared for levels of Varroa destructor infestation in 3 different ecological regions in Mexico. The 300 colonies that were studied were located in subtropical, temperate sub-humid, and temperate dry climates. The morphotype and mitotype of adult bees as well as their rates of infestation by varroa mites were determined. Additionally, the number of combs with brood and covered with bees was recorded for each colony. The highest frequency of colonies that were classified as African-derived was found in the subtropical environment, whereas the lowest occurred in the temperate dry region. Overall, the colonies of African genotype had significantly lower mite infestation rates (3.5±0.34%) than the colonies of European genotype (4.7±0.49%) regardless of the region sampled. Significant effects of genotype and region on Varroa infestation rates were evident, and there were no differences in bee population or capped brood between genotypes. Mite infestation levels were significantly lower in the colonies of the temperate dry region than in the colonies of the other 2 regions. These results are discussed within the context of results from studies that were previously conducted in Brazil. This is the first study that demonstrates the effects of Africanization and ecological environment on V. destructor infestation rates in honey bee colonies in North America.

Reproductive biology of Varroa destructor in Africanized honey bees ( Apis mellifera )

Abstract: Since its first contact with Apis mellifera, the population dynamics of the parasitic mite Varroa destructor varies from one region to another. In many regions of the world, apiculture has come to depend on the use of acaricides, because of the extensive damage caused by varroa to bee colonies. At present, the mite is considered to contribute to the recent decline of honey bee colonies in North America and Europe. Because in tropical climates worker brood rearing and varroa reproduction occurs all year round, it could be expected that here the impact of the parasite will be even more devastating. Yet, this has not been the case in tropical areas of South America. In Brazil, varroa was introduced more than 30 years ago and got established at low levels of infestation, without causing apparent damage to apiculture with Africanized honey bees (AHB). The tolerance of AHB to varroa is apparently attributable, at least in part, to resistance in the bees. The low fertility of this parasite in Africanized worker brood and the grooming and hygienic behavior of the bees are referred as important factors in keeping mite infestation low in the colonies. It has also been suggested that the type of mite influences the level of tolerance in a honey bee population. The Korea haplotype is predominant in unbalanced host-parasite systems, as exist in Europe, whereas in stable systems, as in Brazil, the Japan haplotype used to predominate. However, the patterns of varroa genetic variation have changed in Brazil. All recently sampled mites were of the Korea haplotype, regardless whether the mites had reproduced or not. The fertile mites on AHB in Brazil significantly increased from 56% in the 1980s to 86% in recent years. Nevertheless, despite the increased fertility, no increase in mite infestation rates in the colonies has been detected so far. A comprehensive literature review of varroa reproduction data, focusing on fertility and production of viable female mites, was conducted to provide insight into the Africanized bee host-parasite relationship.

Simplified methods of evaluating colonies for levels of Varroa Sensitive Hygiene (VSH)

Abstract: SummaryVarroa Sensitive Hygiene (VSH) is a trait of honey bees, Apis mellifera, that supports resistance to Varroa destructor mites. Components of VSH were evaluated to identify simple methods for selection of the trait. Mite population growth was measured in colonies with variable levels of VSH in two field trials using 24 and 16 colonies. Mite population growth was significantly lower in VSH and hybrid colonies than in control (i.e., unselected) colonies. In resident brood with mite infestations below 5%, the percentage of uncapped pupal cells did not differ significantly among VSH, hybrid and control colonies, but the percentage of recapped cells was highest in VSH colonies (P = 0.03). When brood from more highly infested colonies (9–49% of pupae infested) was introduced for forty hours, VSH colonies reduced infestation more than control colonies (P< 0.01) but final mite fertility was similar (P= 0.12). When infested brood was exposed in colonies for one week, VSH colonies reduced both mite fertility (...

The removal of capped drone brood: an effective means of reducing the infestation of varroa in honey bee colonies

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.

Perspectives on hygienic behavior in Apis mellifera and other social insects

Abstract: Hygienic behavior in honey bees, Apis mellifera, has been studied for over 80 years with the aim of understanding mechanisms of pathogen and parasite resistance and colony health. This review emphasizes the underlying behavioral mechanisms of hygienic behavior in honey bees and when known, in other social insects. We explore the relationship between honey bee hygienic behavior toward diseased brood and Varroa-parasitized brood (Varroa-sensitive hygiene, VSH); the timing of hygienic removal of diseased, Varroa-infested, and virus-infected brood relative to risk of transmission that can affect colony fitness; and the methods, utility, and odorants associated with different assays used to select colonies for resistance to diseases and Varroa. We also provide avenues for future research that would benefit honey bee health and survivorship.