Showing papers on "Varroa sensitive hygiene published in 2010"
TL;DR: This review provides a survey of the current knowledge in the main fields of Varroa research including the biology of the mite, damage to the host, host tolerance, tolerance breeding andVarroa treatment and comments on the few examples of natural tolerance in A. mellifera.
1,260 citations
TL;DR: The role that pesticides and their residues in hive products may play in colony collapse disorder and other colony problems is discussed.
Abstract: Until 1985 discussions of pesticides and honey bee toxicity in the USA were focused on pesticides applied to crops and the unintentional exposure of foraging bees to them. The recent introduction of arthropod pests of honey bees, Acarapis woodi (1984), Varroa destructor (1987), and Aethina tumida (1997), to the USA have resulted in the intentional introduction of pesticides into beehives to suppress these pests. Both the unintentional and the intentional exposure of honey bees to pesticides have resulted in residues in hive products, especially beeswax. This review examines pesticides applied to crops, pesticides used in apiculture and pesticide residues in hive products. We discuss the role that pesticides and their residues in hive products may play in colony collapse disorder and other colony problems. Although no single pesticide has been shown to cause colony collapse disorder, the additive and synergistic effects of multiple pesticide exposures may contribute to declining honey bee health.
556 citations
TL;DR: This work addresses the question of how Varroa contributes to the recent surge in honey bee colony losses and describes the interactions between different stresses involved.
Abstract: 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.
532 citations
TL;DR: Concern for honey bees in the United States has been magnified by their vital role in agriculture, and what are the implications for agriculture?
Abstract: Over the past few years, the media have frequently reported deaths of honey bee (Apis mellifera L.) colonies in the United States, Europe, and Japan. Most reports express opinions but little hard science. A recent historical survey (1) pointed out that extensive colony losses are not unusual and have occurred repeatedly over many centuries and locations. Concern for honey bees in the United States has been magnified by their vital role in agriculture. The California almond industry alone is worth $2 billion annually and relies on over 1 million honey bee hives for cross-pollination. So what is killing honey bee colonies worldwide, and what are the implications for agriculture?
263 citations
TL;DR: This review reports the development of two breeding successes that have produced honey bees of commercial quality that do not require pesticide treatment to control Varroa, highlights other traits that could be combined to increase resistance and examines the potential uses of marker-assisted selection (MAS) for breeding forVarroa resistance.
Abstract: Breeding for resistance to Varroa destructor in North America provides the long-term solution to the economic troubles the mite brings. This review reports the development of two breeding successes that have produced honey bees of commercial quality that do not require pesticide treatment to control Varroa, highlights other traits that could be combined to increase resistance and examines the potential uses of marker-assisted selection (MAS) for breeding for Varroa resistance. Breeding work continues with these stocks to enhance their commercial utility. This work requires knowledge of the mechanisms of resistance that can be further developed or improved in selected stocks and studied with molecular techniques as a prelude to MAS. Varroa resistance / breeding program / Russian honey bees / Varroa-sensitive hygiene / marker-assisted selection
185 citations
TL;DR: In this paper, the authors studied the causes of honey bee colony losses in Canada and found that honey bee colonies in Canada experienced the highest number of colony deaths in the last decade.
Abstract: (2010). Honey bee colony losses in Canada. Journal of Apicultural Research: Vol. 49, Honey bee colony losses, pp. 104-106.
168 citations
TL;DR: Honey bees are not a highly sensitive species to insecticides overall, or even to specific classes of insecticides, and all pesticides should be used in a way that minimizes honey bee exposure, so as to minimize possible declines in the number of bees and/or honey contamination.
Abstract: BACKGROUND: Honey bees (Apis mellifera L.) are among the most important pollinators in natural and agricultural settings. They commonly encounter insecticides, and the effects of insecticides on honey bees have been frequently noted. It has been suggested that honey bees may be (as a species) uniquely sensitive to insecticides, although no comparative toxicology study has been undertaken to examine this claim. An extensive literature review was conducted, using data in which adult insects were topically treated with insecticides. The goal of this review was to summarize insecticide toxicity data between A. mellifera and other insects to determine the relative sensitivity of honey bees to insecticides.
RESULTS: It was found that, in general, honey bees were no more sensitive than other insect species across the 62 insecticides examined. In addition, honey bees were not more sensitive to any of the six classes of insecticides (carbamates, nicotinoids, organochlorines, organophosphates, pyrethroids and miscellaneous) examined.
CONCLUSIONS: While honey bees can be sensitive to individual insecticides, they are not a highly sensitive species to insecticides overall, or even to specific classes of insecticides. However, all pesticides should be used in a way that minimizes honey bee exposure, so as to minimize possible declines in the number of bees and/or honey contamination. Copyright © 2010 Society of Chemical Industry
130 citations
TL;DR: In this article, the role of Varroa destructor for honey bee colony losses in Norway was investigated and it was shown that the Varroaa destructor was a major cause of bee colony loss in Norway.
Abstract: (2010). The role of Varroa destructor for honey bee colony losses in Norway. Journal of Apicultural Research: Vol. 49, Honey bee colony losses, pp. 124-125.
81 citations
TL;DR: Results suggest that the varroa mite can exploit the differences in the cuticular composition of its host for a refined selection that allows it to reach a brood cell and start reproduction.
Abstract: The parasitic mite, Varroa destructor, is the most important threat for apiculture in most bee-keeping areas of the world. The mite is carried to the bee brood cell, where it reproduces, by a nurse bee; therefore the selection of the bee stage by the parasite could influence its reproductive success. This study investigates the role of the cuticular hydrocarbons of the European honeybee (Apis mellifera) in host-selection by the mite. Preliminary laboratory bioassays confirmed the preference of the varroa mite for nurse bees over pollen foragers. GC-MS analysis of nurse and pollen bees revealed differences in the cuticular hydrocarbons of the two stages; in particular, it appeared that pollen bees have more (Z)-8-heptadecene than nurse bees. Laboratory experiments showed that treatment of nurse bees with 100 ng of the pure compound makes them repellent to the varroa mite. These results suggest that the mite can exploit the differences in the cuticular composition of its host for a refined selection that allows it to reach a brood cell and start reproduction. The biological activity of the alkene encourages further investigations for the development of novel control techniques based on this compound.
58 citations
TL;DR: The results suggest that neither egg-laying by foundress mites nor mite offspring are the stimuli that trigger hygienic removal of mite-infested pupae by VSH bees, and it may be that hyGienic activities such as the uncapping of brood cells inhibits or disrupts reproduction by varroa mites.
Abstract: Varroa sensitive hygiene (VSH) is a trait of honey bees, Apis mellifera L. (Hymenoptera: Apidae), which supports resistance to Varroa destructor Anderson & Trueman. VSH is the hygienic removal of mite-infested pupa. Bees selectively bred for VSH produce colonies in which the fertility of mites decreases over time. In addition, mite fertility decreases after infested brood is exposed to VSH bees for 1 wk. The purpose of this study was to decide whether the reduction in mite fertility is caused by selective removal of mites that produce offspring. Initially, we monitored changes in a small patch of capped brood during exposure to VSH bees at 2-h intervals through 60 h, which provided a reference for the subsequent experiment. The first test showed that VSH bees uncapped, recapped, and began to remove many pupae in ≈2 h. The approach in the second experiment was to compare the percentage of fertile mites from brood exposed to VSH bees for a 3-h period to the percentage of fertile mites in brood that was protected from hygiene by a screen. There were no significant differences in fertility between mites on pupae that were being removed by the bees and mites on protected pupae. These results suggest that neither egg-laying by foundress mites nor mite offspring are the stimuli that trigger hygienic removal of mite-infested pupae by VSH bees. It may be that hygienic activities such as the uncapping of brood cells inhibits or disrupts reproduction by varroa mites.
51 citations
TL;DR: This work presents a meta-analysis of the honey beekeeping practices in Italy over a 25-year period from 1991 to 2002, which revealed clear trends in honeybee behaviour and in particular in the Lazio-Toscana region.
Abstract: (2010). Honey bee colony losses in Italy. Journal of Apicultural Research: Vol. 49, Honey bee colony losses, pp. 119-120.
TL;DR: 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.
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.
TL;DR: The honey bee was introduced primarily for honey production but has become the most important insect pollinator of seed, vegetable, fruit crops and pastures and the spread of the varroa mite has increased the cost of managing honey bee hives.
Abstract: Eight bee species have been deliberately released into New Zealand since the 1830's. The honey bee (Apis mellifera L.) was introduced primarily for honey production but has become the most important insect pollinator of seed, vegetable, fruit crops and pastures. The remaining species (Bombus terrestris (L.), B. hortorum (L.), B. ruderatus (F.), B. subterraneus (L.), Megachile rotundata (F.), Nomia melanderi (Cockerell), Osmia coerulescens (L.) were introduced to pollinate either red clover (Trifolium pratense) or lucerne (Medicago sativa). The honey bee has almost exclusively been relied upon for crop pollination although species of Bombus and M. rotundata are occasionally used commercially. The spread throughout New Zealand of the varroa mite (Varroa destructor Anderson & Trueman), a parasite that exclusively kills honey bees, has increased the cost of managing honey bee hives. The use of alternative bee species for crop pollination may reduce the potential impact of factors infl uencing the availability...
Journal Article•
TL;DR: A system of nonlinear ordinary dif- ferential equations for the dependent variables: number of mites that carry the virus, number of healthy bees and number of sick bees indicates that bee colonies in which the virus is present can, over years, function seemingly like healthy colonies before they decline and disappear rapidly.
Abstract: We present a simple mathematical model of the infestation of a honeybee colony by the Acute Paralysis Virus, which is carried by parasitic varroa mites (Varroa destructor). This is a system of nonlinear ordinary dif- ferential equations for the dependent variables: number of mites that carry the virus, number of healthy bees and number of sick bees. We study this model with a mix of analytical and computational techniques. Our results indicate that, depending on model parameters and initial data, bee colonies in which the virus is present can, over years, function seemingly like healthy colonies before they decline and disappear rapidly (e.g. Colony Collapse Disor- der, wintering losses). This is a consequence of the fact that a certain number of worker bees is required in a colony to maintain and care for the brood, in order to ensure continued production of new bees.
TL;DR: The relatively low heritability of grooming behaviour in the three generations of queens examined indicate that breeding colonies for grooming behaviour only cannot be advised to beekeepers whose aim is to breed bees highly tolerant to Varroa mites.
Abstract: Grooming behaviour is considered an important defensive mechanism of honey bees against Varroa mites. The aim of this study was to reveal whether grooming behaviour is a useful criterion in breeding of Varroa-tolerant bees. To obtain a reliable evaluation the environmental influences were excluded. The degree of grooming potential was estimated by the percentage of damaged mites in the total number of fallen mites. The heritability of grooming behaviour throughout the three consecutive generations of queens was assessed by mother-daughter regression method. Among unselected queens, expressed grooming behaviour was recorded only in colonies with F1 queens (36.27%), but not in colonies with P queens and F2 queens (33.69%, 31.66%, respectively). Significant differences in grooming behaviour were found between colonies of P and F1 queens (p 0.05) difference among them. Nevertheless, the relatively low heritability of grooming behaviour in the three generations of queens examined (h2yx=0.49±0.02; h2zx=0.18±0.01; h2zy=0.16±0.01) indicate that breeding colonies for grooming behaviour only cannot be advised to beekeepers whose aim is to breed bees highly tolerant to Varroa mites.
TL;DR: The honey bee winter loss survey for England, 2007–8, shows that honey bee colony losses have increased since the last survey in 2007, although the total number of colonies has not changed significantly.
Abstract: (2010). Honey bee winter loss survey for England, 2007–8. Journal of Apicultural Research: Vol. 49, Honey bee colony losses, pp. 111-112.
TL;DR: It is concluded that if transmitted by the mite, the virus fails to become established as an overt infection in the honey bee, and the reasons why CWV has apparently increased in incidence in the UK since the arrival of V. destructor remain unclear.
Abstract: SummaryCloudy wing virus (CWV) is a little studied small icosahedral virus commonly found in honey bees (Apis mellifera), especially in collapsing colonies infested by Varroa destructor, providing circumstantial evidence that the mite may act as a vector. This study investigated the potential relationship between V. destructor, CWV and honey bees in 29 naturally infested colonies in the UK. We found that CWV was detected in less than half of the colonies, despite all having been infested by V. destructor. In contrast to several other viruses, we also found no evidence that V. destructor is able to vector CWV when feeding, and conclude that if transmitted by the mite, the virus fails to become established as an overt infection in the honey bee. The reasons why CWV has apparently increased in incidence in the UK since the arrival of V. destructor therefore remain unclear.
TL;DR: The goal of this study was to test the capability of the glutathione-S-transferase enzyme inhibitors diethyl maleate and curcumin, which should interfere minimally with honey bee detoxification, to elevate the toxicity of tau-fluvalinate to a population of varroa mites.
Abstract: The varroa mite (Varroa destructor Anderson and Trueman) is a devastating pest of honey bees (Apis mellifera L.). Beekeepers have relied on the pyrethroid pesticide tau-fluvalinate as a principal agent of varroa mite control. While this miticide was quite effective at controlling varroa mites through the 1990s, its efficacy has waned as resistance to tau-fluvalinate has appeared in many populations of mites. Resistance in some populations of varroa mites has been associated with elevated detoxification of tau-fluvalinate. Honey bees tolerate miticidal tau-fluvalinate applications principally through rapid detoxification mediated by cytochrome-P450 mono-oxygenases, with the other detoxification enzyme families, the carboxylesterases and glutathione-S-transferases, playing much smaller roles in miticide tolerance. The goal of this study was to test the capability of the glutathione-S-transferase enzyme inhibitors diethyl maleate and curcumin, which should interfere minimally with honey bee detoxifi...
TL;DR: 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.
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.
TL;DR: The isolation of the mitosporic fungus Beauveria bassiana from varroa mites, Varroa destructor, in capped worker brood cells of honey bees, Apis mellifera, is reported, to be the first record of B.bassiana from mites collected from bee brood.
Abstract: We report on the isolation of the mitosporic fungus Beauveria bassiana from varroa mites, Varroa destructor, in capped worker brood cells of honey bees, Apis mellifera. To our knowledge, this is the first record of B. bassiana from mites collected from bee brood. The brood chamber is the area of the hive where bees maintain high constant temperatures of 33–36 ◦C (Le Conte et al., 1990). An entomopathogenic fungus may be less efficacious because of poor germination at the high temperatures inside brood cells. Natural enemies of the varroa mite are few and, until recently, included no records of fungal pathogens (Chandler et al., 2001). However, a number of studies have shown that varroa mites are highly susceptible to infection by a range of entomopathogenic fungi, including B. bassiana (James, 2009). Many entomopathogenic fungi have a ubiquitous distribution and a wide host range, thus one might expect foraging bees to frequently carry fungus conidia into the bee hive from their environment. The lack of observed natural infections of varroa mites by these fungi could be due to a combination of hygienic behaviour of worker bees and the harsh environmental conditions in bee colonies. Nevertheless, Meikle et al. (2006) isolated B. bassiana from approximately 0.2% of varroa mites collected from a number of apiaries in southern France and documented that natural infections could indeed be found. B. bassiana has also been reported from varroa mites in southern Spain (Garcia-Fernandez et al., 2008).
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TL;DR: Testing honey bee colonies with no brood or little brood in beehive conditions in West-Viru County, Estonia found a water solution of 0.5% OA gave effective control of the mite and was not toxic to bees whereas higher concentrations of OA were highly toxic to Bees.
Abstract: We studied the toxicity of water solutions contain ing various concentrations of oxalic acid dihydrate to bees and Varroa mites ( Varroa destructor ) using by spraying honey bee (Apis mellifera ) colonies with no brood or little brood in beehive conditions in West-Viru County, Estonia. A water solution of 0.5% OA gave effective control of the mite and was not toxic to bees whereas higher concentrations of OA ( 1.0 and 1.5%) were highly toxic to bees. In autumn, spraying test colonies that had little capp ed brood once or twice with a 0.5% OA solution gave effective mite control (92.94 ± 0.01% and 91.84 ± 0.02%, respectively) with no noticeable toxicity to bees.
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TL;DR: The occurrence of damaged mites in the colonies of the three subspecies in the summer and winter months provides evidence for active defense mechanisms against the parasitic mite Varroa destructor helping in reducing the initial mite mother population.
Abstract: The seasonal variations in the number of damaged Varroa mites in the colonies of Apis mellifera ligustica, A. mellifera carnica and A. mellifera syriaca were studied using eight colonies for each honeybee subspecies. The results showed that the damaged mites in colonies of all three honey bee subspecies were noticed all over the year. Monthly changes in grooming behavior in the three subspecies showed the same general trend, the maximum percentages of the damaged mites were recorded during June correlated with high workers populated colonies and not correlated with the high Varroa infestation rates in the colonies. The occurrence of damaged mites in the colonies of the three subspecies in the summer and winter months provides evidence for active defense mechanisms against the parasitic mite Varroa destructor helping in reducing the initial mite mother population.
01 Jan 2010
TL;DR: This research work has been conducted on plants extracts reducing the mite population of Varroa destructor and has obtained promising results for extracts of yew and walnut.
Abstract: Varroa destructor is an external parasitic mite that attacks honey bees Apis cerana and Apis mellifera. Varroa mites can be controlled through commercially available miticides as well as non-chemical means. Our research work has been conducted on plants extracts reducing the mite population. We have obtained promising results for extracts of yew and walnut.
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TL;DR: Positive results of high efficiency of substa nces against Varroa allow to elaborate model to exe cut destroying mite in organic apiaries.
Abstract: In the last three years, to destroy mite Varroa des tructor we stated high efficiency against Varroa of Oxalic acid and different substances (organic acids and essential oils) w hich could be used in organic apiary. Using Oxalic cid and Formic acid is possible in period when there is no brood in col onies, what is possible mainly in October and Novem ber. Using acids this time causes that to the moment of using them, in co lonies intensive development of mites starts, so su bstances against Varroa ought to be used after the latest honey harvest (the end of July and August – Api Life Var) and la ter Oxalic and Formic acid. Positive results of high efficiency of substa nces against Varroa allow to elaborate model to exe cut destroying mite in organic apiaries. It is important that there is not t be residues of substances against mite in honey . It is needed to use every year various anti Varroa substances.
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TL;DR: Results include: bee colonies headed by queens selected for their increased hygienic behavior exhibited reduced nosema spore loads, which lasted during the early spring and was not detected at a later date, and older, over-wintered, hives exhibited higherSpore loads than newly made colonies.
Abstract: Bee colonies are being decimated by new diseases and by older diseases that have become more virulent. Nosema is a disease that contributes to these losses. Many recommendations concerning queen type in the past have focused on honey production. Extension educators need information on how queen source and colony age can be used to manage disease. Results include: bee colonies headed by queens selected for their increased hygienic behavior exhibited reduced nosema spore loads. This effect lasted during the early spring and was not detected at a later date. Older, over-wintered, hives exhibited higher spore loads than newly made colonies.
01 Jan 2010
01 Jan 2010
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TL;DR: The sugar shake method was more sensitive, reliable, and efficient regarding cost and labor and the action threshold was proposed as 5% infestation of varroa mites on adult honeybees in consideration of various uncertainties discussed here.
Abstract: The ectoparasite mite Varroa destructor is the most serious pest of honeybee (Apis mellifera L.). In developing integrated mite management system, monitoring is the first priority. Here, we compared the sugar shaking and sticky board methods for the precise and efficient monitoring of varroa mite. Further, the distribution of varroa mite inside the hive was studied. Along with varroa mite and honeybee colony monitoring, we proposed an economic injury level and action threshold. The sugar shake method was more sensitive, reliable, and efficient regarding cost and labor. Between these two methods, mite densities were significantly correlated with r²=0.815. Between the bottom and super chambers of the hive, mite densities were not different. Even though there was no difference in mite density between each comb, mite densities were significantly higher in the middle part of the comb. The economic injury level of varroa mite in the hive, which was based on the mite densitywhen the honeybee population started to decline, was measured to be 22 per 100 bees by the sugar shake method and 12 per day by the sticky board method. The action threshold was proposed as 11 per 100 bees by sugar shaking and 6 per day by the sticky board method. However, the practical guideline for varroa control is suggested as 5% infestation of varroa mites on adult honeybees in consideration of various uncertainties discussed here.
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