Practical Sampling Plans for <I>Varroa destructor</I> (Acari: Varroidae) in <I>Apis mellifera</I> (Hymenoptera: Apidae) Colonies and Apiaries

Abstract

The parasitic mite Varroa destructor Anderson & Trueman (Acari: Varroidae) is arguably the most detrimental pest of the European-derived honey bee, Apis mellifera L. Unfortunately, beekeepers lack a standardized sampling plan to make informed treatment decisions. Based on data from 31 commercial apiaries, we developed sampling plans for use by beekeepers and researchers to estimate the density of mites in individual colonies or whole apiaries. Beekeepers can estimate a colony's mite density with chosen level of precision by dislodging mites from approximately to 300 adult bees taken from one brood box frame in the colony, and they can extrapolate to mite density on a colony's adults and pupae combined by doubling the number of mites on adults. For sampling whole apiaries, beekeepers can repeat the process in each of n = 8 colonies, regardless of apiary size. Researchers desiring greater precision can estimate mite density in an individual colony by examining three, 300-bee sample units. Extrapolation to density on adults and pupae may require independent estimates of numbers of adults, of pupae, and of their respective mite densities. Researchers can estimate apiary-level mite density by taking one 300-bee sample unit per colony, but should do so from a variable number of colonies, depending on apiary size. These practical sampling plans will allow beekeepers and researchers to quantify mite infestation levels and enhance understanding and management of V. destructor.

Seasonal benefits of a natural propolis envelope to honey bee immunity and colony health

“…All assessments consisted of: (1) estimating the adult bee population size by counting the number of frames covered with bees for each box (Nasr et al, 1990); (2) estimating the total amount of worker brood by using a grid (2.56 cm 2 ) over a frame and counting the number of squares filled with sealed or unsealed brood (Nasr et al, 1990); (3) collecting a sample of 300 adult bees from the brood area in 70% ethanol and quantifying Varroa and Nosema spp. levels in the laboratory following previously published methods (Lee et al, 2010;Spivak and Reuter, 2001); (4) inspecting for the presence of clinical symptoms of diseases in the field [e.g. American foulbrood (AFB)-infected larvae, as noted by the presence of sunken wax capping and uncapped cells containing discolored, ropy brood]; and (5) noting colony survivorship as dead or alive.…”

High Varroa mite abundance influences chemical profiles of worker bees and mite–host preferences

“…The sampled bees were killed by freezing and then inspected for the presence of phoretic mites. This sampling procedure will yield colony mite abundance with adequate precision (Lee et al, 2010). Variation in the mite abundance of the 10 sampled colonies used for the bioassays was remarkable, ranging from less than 0.05 up to about 0.53.…”

“…At least 20 mites per colony were tested for each treatment in the two bioassays. We chose the threshold of 0.10 mite abundance as it has been reported (Lee et al, 2010) to be the maximum limit after which a colony needs to be treated.…”

PARASITISM BY VARROA AND Nosema sp. IN BEEHIVES USED FOR APPLE TREE POLLINATION

“…The increased number of pupae is related to the increased incidence of V. destructor (PICCIRILLO; DE JONG, 2003;MESSAGE;GONÇALVES, 1995). This is due to the interaction between feeding bees and the offspring during swarm foraging, which facilitates the movement of V. destructor females through the hive (LEE et al, 2010). The circulation of adult bees favors the spread of V. destructor from one area to another within the hive.…”

“…in A. mellifera hives (PEGORARO et al, 2013;PETTIS et al, 2013). The reduction of breeding areas and food reserves in the A. mellifera hives used for pollination services indicates physiological and behavioral changes that compromise the maintenance and development of hives (LEE et al, 2010). Data on the occurrence of V. destructor and Nosema sp., and the effect of these parasites on population variations in A. mellifera hives used in apple pollination in Brazil are limited.…”