Showing papers on "Varroa sensitive hygiene published in 2001"
TL;DR: Results indicate that hygienic colonies with queens mated naturally to unselected drones had significantly fewer mites on adult bees and within worker brood cells than Starline colonies for up to 1 yr without treatment in a commercial, migratory beekeeping operation.
Abstract: Honey bee (Apis mellifera L.) colonies bred for hygienic behavior were tested in a large field trial to determine if they were able to resist the parasitic mite Varroa destructor better than unselected colonies of "Starline" stock. Colonies bred for hygienic behavior are able to detect, uncap, and remove experimentally infested brood from the nest, although the extent to which the behavior actually reduces the overall mite-load in untreated, naturally infested colonies needed further verification. The results indicate that hygienic colonies with queens mated naturally to unselected drones had significantly fewer mites on adult bees and within worker brood cells than Starline colonies for up to 1 yr without treatment in a commercial, migratory beekeeping operation. Hygienic colonies actively defended themselves against the mites when mite levels were relatively low. At high mite infestations (.15% of worker brood and of adult bees), the majority of hygienic colonies required treatment to prevent collapse. Overall, the hygienic colonies had similar adult populations and brood areas, produced as much honey, and had less brood disease than the Starline colonies. Thus, honey bees bred for hygienic behavior performed as well if not better than other commercial lines of bees and maintained lower mite loads for up to one year without treatment.
158 citations
TL;DR: Arolled field study of the development of populations of V. destructor in far-eastern Russia shows that P colonies have a strong, genetically based resistance to the parasite.
Abstract: Varroa destructoris a parasitic mite of the Asian honey bee, Apis cerana. Owing to host range expansion, it now plagues Apis mellifera, the world's principal crop pollinator and honey pro- ducer. Evidence from A. mellifera in far-eastern Russia, Primorsky (P) originating from honey bees imported in the mid 1800's, suggested that many colonies were resistant toV. destructor. A con- trolled field study of the development of populations of V. destructor shows that P colonies have a strong, genetically based resistance to the parasite. As control colonies (D) were dying with infesta- tions of ca. 10 000 mites, P colonies were surviving with infestations of ca. 4 000 mites. Several characteristics of the P bees contributed to suppressing the number of mites parasitizing their colonies. Apis mellifera / mite resistance / Varrao destructor / Russia / disease resistance / natural selection
123 citations
TL;DR: Negative correlations were found between the mite population growth and both the total number of mites and the number of injured mites collected from the bottom-boards, and differences were found for hygienic behavior but the effect of this mechanism was not clear.
Abstract: This study was conducted to determine the existence of phenotypic and genotypic vari- ation in the ability of honey bee colonies to restrain the population growth of the mite Varroa destruc- tor Anderson and Trueman, and to asses the relative effect of four characteristics that may confer tol- erance to honey bees toward the mite. Fifty-eight colonies infested with an equal number of mites were sampled monthly during six months to determine their levels of infestation on adult bees and in worker brood. At the end of this period, 16 colonies were selected to study the effect of grooming behavior, hygienic behavior, brood attractiveness, and host-induced non-reproduction. The infesta- tion-levels in adult bees varied significantly between colonies (range: 6.6-44.7%), but no differ- ences were found in the brood infestation levels. The variation between colonies was partially genetic in origin. Grooming behavior explained most of the variation ( r 2 = 0.38). Negative correlations were found between the mite population growth and both the total number of mites and the number of injured mites collected from the bottom-boards (r = -0.65 and r = -0.76, respectively). Differences were found for hygienic behavior but the effect of this mechanism was not clear. No differences were found among colonies for brood attractiveness, or for the effect of the brood on the mite's reproduction.
120 citations
TL;DR: This paper reviews prospective biological control agents of the varroa mite, Varroa destructor n.
Abstract: This paper reviews prospective biological control agents of the varroa mite, Varroa destructor n. sp. (Acari, Mesostigmata). This ectoparasite has caused severe damage to populations of the European honeybee, Apis mellifera , world-wide in recent years. To date, no promising natural enemies of varroa species have been identified on A. mellifera or its original host, Apis cerana . Therefore, biological control will probably require natural enemies from other hosts. The following groups of organisms were reviewed as potential biological control agents: predatory mites, parasitoids and entomopathogens (nematodes, protozoa, viruses, Bacillus thuringiensis , rickettsiae, and fungi). The candidate groups were ranked according to their lethality to Acari, likely ability to operate under the physical conditions of honeybee colonies, ease of targeting, and ease of mass-production. Preferential consideration was given to the natural enemies of Acari that occupy taxonomic groups close to varroa. Entomopathogenic fun...
74 citations
TL;DR: It is demonstrated that honey bees, Apis mellifera L, can express a high level of resistance to Varroa destructor Anderson & Trueman when bees were selected for only one resistant trait and that a significant level of mite-resistance was retained when these queens were free-mated with unselected drones.
Abstract: This study demonstrated (1) that honey bees, Apis mellifera L, can express a high level of resistance to Varroa destructor Anderson & Trueman when bees were selected for only one resistant trait (suppression of mite reproduction); and (2) that a significant level of mite-resistance was retained when these queens were free-mated with unselected drones. The test compared the growth of mite populations in colonies of bees that each received one of the following queens: (1) resistant--queens selected for suppression of mite reproduction and artificially inseminated in Baton Rouge with drones from similarly selected stocks; (2) resistant x control--resistant queens, as above, produced and free-mated to unselected drones by one of four commercial queen producers; and (3) control--commercial queens chosen by the same four queen producers and free-mated as above. All colonies started the test with approximately 0.9 kg of bees that were naturally infested with approximately 650 mites. Colonies with resistant x control queens ended the 115-d test period with significantly fewer mites than did colonies with control queens. This suggests that beekeepers can derive immediate benefit from mite-resistant queens that have been free-mated to unselected drones. Moreover, the production and distribution of these free-mated queens from many commercial sources may be an effective way to insert beneficial genes into our commercial population of honey bees without losing the genetic diversity and the useful beekeeping characteristics of this population.
72 citations
TL;DR: Feed tests revealed that application of IGRs to larvae may result in death and larval ejec- tion by workers, malformed larvae and pupae with typical rimmed eyes, or malformed adults.
Abstract: The insect growth regulators (IGRs) are ecdysone or juvenile hormone mimics, or chitin synthesis inhibitors. They are more likely to be hazardous to larval insects than to adults. Application of JH mimics to adult honey bees may affect foraging behaviour and some physiological traits. Top- ical and feeding tests revealed that application of IGRs to larvae may result in death and larval ejec- tion by workers, malformed larvae and pupae with typical rimmed eyes, or malformed adults. Sev- eral laboratory "larvae tests" using artificially contaminated diets have been described for honey bees and bumble bees. Field and cage methods have also been published for honey bees and bumble bees respectively. Diflubenzuron was generally safe for honey bee brood in fields treated at 35 to 400 g.ha -1 a.i. and harmful to bumble bees at 300 g .ha -1 a.i. Fenoxycarb was safe for bumble bees at 1 200 g.ha -1 a.i. and hazardous to honey bees causing damage to honey bee brood at 140 g .ha -1 . insect growth regulator / honey bee / non-Apis bee / toxicity / risk assessment
68 citations
TL;DR: A laboratory bioassay was developed to measure the intensity and effectiveness of grooming responses by worker bees artificially infested with one Varroa mite, and Africanized bees responded significantly faster and more intensively than Carniolan workers.
Abstract: Grooming behavior is considered a varroosis tolerance factor of Africanized honey bees, but this behavior is difficult to evaluate directly within the honey bee colony. A laboratory bioassay was developed to measure the intensity and effectiveness of grooming responses by worker bees artificially infested with one Varroa mite. At a study site in tropical Brazil, the sequence of seven well- defined grooming reactions towards mites of different colonial origin was compared. In a total of 226 assays, Africanized bees responded significantly faster and more intensively than Carniolan workers. But there were no statistical differences in the removal of mites according to the bee types. Even extensive grooming behavior never resulted in damage or death of the mites. The possible use of the bioassay as a screening for the extent of the grooming behavior is discussed. Africanized honey bee / behavioral trait / bioassay / grooming / Varroa destructor / Carnolian bee
65 citations
TL;DR: A synergistic interaction between tracheal and V. destructor mites should be applied in dually infested colonies, even iftracheal mites alone are not having an impact.
Abstract: Colony mortality and productivity were compared between honey bee (Apis mellifera) colonies infested by zero, one or both species of parasitic mites ( Acarapis woodior Varroa destruc- tor). Mortality, bee and mite populations, sealed brood, and stores were monitored for 16 months, begin- ning in May. By the following March, 5 out of 6 colonies with both mites were dead, but no other colonies died until September, when 3 out of 4 V. destructor colonies were dead. Dually infested colonies initially had more honey stores, but were dead by March. At that point V. destructor colonies had significantly less worker brood, fewer adult bees and more honey than colonies with no mites or tracheal mites (Acarapis woodi). The colonies with tracheal mites ( n = 9) and no mites (n = 8) did not differ in any productivity parameter measured. These results suggest a synergistic interaction between tracheal and V. destructor mites, treatments against tracheal mites should be applied in dually infested colonies, even if tracheal mites alone are not having an impact. Varroa destructor / Acarapis woodi / colony productivity / colony mortality
47 citations
TL;DR: It is concluded that host kairomones play a role in the host acquisition process, but there is no evidence to support the hypothesis that mites use these substances to differentiate between worker and drone brood.
Abstract: .Varroa destructor is a parasitic mite of the honey bee species Apis cerana Fabr. and A. mellifera L. Mature females reproduce on the immature stages of their hosts, producing more viable female offspring on drone hosts than on worker hosts. Thus, immature drones are more likely to be infested with mites than immature workers. To investigate the hypothesis that differences in host chemistries underlie the biased distribution of mites between worker and drone brood, the arrestment responses of mites to solvent extracts of a number of stimuli normally encountered by a mite during its life cycle were measured. Mites were arrested by cuticular extracts of worker and drone larvae obtained at 0, 24 and 48 h prior to the time when cell capping is completed. Mites were also arrested by extracts of worker and drone, brood food and cocoons, and by a blend of synthetic fatty acid esters previously shown to be active in the host acquisition process. In a wind tunnel bioassay, mites were attracted to odours from living fifth-instar worker and drone larvae, but not to volatiles from cocoons, brood food or a blend of fatty acid esters. The sex of the host was not an important factor affecting the behavioural responses of the mites in any assay. We conclude that host kairomones play a role in the host acquisition process, but we found no evidence to support the hypothesis that mites use these substances to differentiate between worker and drone brood.
39 citations
TL;DR: Findings suggest that polar products may act as chemostimuli for recognition of V. destructor by honey bees and further study will be necessary to determine which polar products are involved and assess grooming and removal behaviour using these products.
Abstract: . One way in which Apis mellifera honey bees resist Varroa destructor is by detection and elimination of nestmates. This study uses behavioural tests and electroanntennography to assess the role of chemostimuli in recognition by honey bees of this acarian ectoparasite. Behavioural tests using living or dead parasites involved observation of honey bee grooming activity (antennation) under controlled conditions in Petri dishes, and removal behaviour (uncapping and elimination of parasitized and unparasitized control brood cells) under natural conditions. Some bees from colonies with both small and large parasite populations showed aggressive behaviour (biting). No difference was observed according to whether the mite was dead or alive. Under natural conditions, bees uncapped more parasitized cells than control cells. Electroantennographic tests were performed to measure sensitivity to various Varroa extracts at three concentrations (10, 20 and 30 Varroa Equivalents). Only 30 Varroa Equivalent methanol extracts made from Varroa collected from brood cells elicited significantly greater antennal response than controls (pure solvent). All three methanol extracts elicited significantly greater antennal response than controls. No response was observed using Varroa extracts made with acetone or hexane. These findings suggest that polar products may act as chemostimuli for recognition of V. destructor by honey bees. Further study will be necessary to determine which polar products are involved in this recognition and assess grooming and removal behaviour using these products.
20 citations
TL;DR: The results corroborate studies that have shown that honey bees possess genetic components for tracheal mite resistance that can be readily enhanced in a breeding program.
Abstract: Two generations of honey bees, Apis mellifera L., selected for resistance to tracheal mites, Acarapis woodi (Rennie), were produced from a foundation stock. The mite resistant lines had significantly low mite abundances and prevalences in each selected generation. The high mite-resistant lines of the first selected generation showed resistance equal to that of bees that had undergone natural selection from tracheal mite infestations for 3 yr in New York. Additionally, the high mite-resistant lines of the second selected generation and Buckfast bees had significantly lower mite abundances and prevalences than honey bees from control colonies which had never been exposed to tracheal mite infestation in Ontario. These results corroborate studies that have shown that honey bees possess genetic components for tracheal mite resistance that can be readily enhanced in a breeding program. The two methods used for evaluating relative resistance of honey bees to tracheal mites, a short-term bioassay and evaluation in field colonies, were positively correlated (rs = 0.64, P < 0.001).
TL;DR: The results do not support the hypothesis that mites become concentrated on the remaining bees as bees die off from the winter cluster, and there is no reason to differentiate the mortality rates of bees and mites during periods when there are no or limited amounts of brood in the colonies.
Abstract: The change in infestation levels of the mite Varroa destructorAnderson and Trueman on adult bees during periods with little or no brood rearing (late October/early November to early Febru- ary) was investigated in 10 colonies for two consecutive years in a Swedish climate (N57°06'E18°16'). The results do not support the hypothesis that mites become concentrated on the remaining bees as bees die off from the winter cluster. When the number of all mites recovered from dead bees or from debris was used to calculate mites per dead bee, the level of infestation per bee was not signif- icantly different between samples of live bee and dead bees. For modelling purposes, we presently find no reason to differentiate the mortality rates of bees and mites during periods when there is no or limited amounts of brood in the colonies, although the connection between bee mortality and mite mortality may not be as direct as previously assumed.
01 Jan 2001
Journal Article•
TL;DR: Conclusions from this research are that varroa is a very serious problem for Turkey, with migratory type management spreading this infection, and honey gathering will be impossible economically, and colony loss probability will be very high at the end of the season.
Abstract: The aim of this research was to investigate the effectiveness of fluvalinate (on wooden bars), amitraz (on paper strips) and coumaphos (liquid) against Varroa jacobsoni in honeybee (Apis mellifera L.) colonies. This research was carried out on 24 A. mellifera colonies in the Cukurova region in spring 1998. The colony strength, the area of sealed brood and the rate of infections were evaluated before and after the chemical applications. The level of varroa contamination for each colony was determined on 200 brood bees at the pupa stage and on 150-200 adult bees. After the application, dead fallen and alive drugged mites and dead bees on the modified bottom board were counted every day for sixteen days. Then the effectiveness of the three chemical applications was determined and the results statistically evaluated with the Henderson-Tilton method. The data obtained were evaluated statistically. Fluvalinate, Amitraz and Coumaphos were 97.3%, 91.1% and 83.4% effective on V. jacobsoni respectively. Colonies in the control group without treatment were strongly affected by varroa, resulting in very low honey yield. Conclusions from this research are that varroa is a very serious problem for Turkey, with migratory type management spreading this infection. If no precautions are taken, honey gathering will be impossible economically, and colony loss probability will be very high at the end of the season.
Journal Article•
TL;DR: The parasite varroa is the major pest affecting apiculture in several parts of the world, but in others the parasite is unknown to many beekeepers because of the lack of knowledge about it.
Abstract: Resumen en: Whereas in several parts of the world varroa is the major pest affecting apiculture, in others the parasite is unknown to many beekeepers because of th...
01 Jan 2001
TL;DR: Varroa jacobsoni mites may invade worker or drone brood cells when worker bees bring them in close contact with these cells.
Abstract: Varroa jacobsoni mites may invade worker or drone brood cells when worker bees bring them in close contact with these cells. The attractive period of drone brood cells is two to three times longer than that of worker brood cells. The attractiveness of brood cells is related to the distance between the larva and the cell rim and the age of the larva. The moment of invasion of the mite into a brood cell is not related to the duration of its stay on adult bees. The fraction of the phonetic mites that invade brood cells is determined by the ratio of the number of suitable brood cells and the size of the colony. The distribution of mites over worker and drone brood in a colony is determined by the specific rates of invasion and the numbers of both brood cell types. Knowledge of mite invasion behaviour has led to effective biotechnical control methods.
TL;DR: Hygienic behaviour forms one of the bases of tolerance of the Asian honey bee (Apis cerana) to varroa and can also play an important role in theolerance of the European honey bees (A. mellifera) towards the mite.
Abstract: SUMMARYHygienic behaviour forms one of the bases of tolerance of the Asian honey bee (Apis cerana) to varroa This behaviour can also play an important role in the tolerance of the European honey bee (A mellifera) towards the mite The hygienic behavioural response of bees over a period of 24 h towards worker brood cells of A mellifera iberica artificially infested with varroa was studied When bees detected cells containing mites, in some instances both brood and mites were removed, whereas in others only the mite was removed When a single mite was placed in each cell, hygienic behaviour was not induced, only 074% of infested cells had mites removed Using two or three mites per cell, this response increased significantly, with 801% and 1662% of infested cells with mites removed, respectively A positive correlation (P < 005, r = 049) was found in hygienic behaviour towards cells artificially infested with two or three mites A second experiment was conducted to compare the response of bees to li
01 Jan 2001
TL;DR: The reproductive behaviour of the mite Varroa jacobsoni was investigated during the summer months in Apis mellifera syriaca colonies in Irbid, Jordan by examining the progeny of the female mother mites in worker and drone cells.
Abstract: The reproductive behaviour of the mite Varroa jacobsoni was investigated during the summer months in Apis mellifera syriaca colonies in Irbid, Jordan. Reproductive rates for mites reaching adulthood were estimated by examining the progeny of the female mother mites in worker and drone cells. The proportions of non-reproducing mites in the worker and drone brood were 9.8% and 4.9%, respectively. The reproductive rate was 2.72 for mites in worker cells and 3.35 for mites in drone cells. The percentage of infested brood with adult mite daughters was 43.9 % for worker and 55% for drone broods. The rate for females reaching adulthood from each original female mite was 0.75 for worker and 1.41 for drone brood.