Does time spent on adult bees affect reproductive success of Varroa mites?

Abstract

Reproduction of Varroajacobsoni Oudemans (Acari: Varroidae) and the number of Varroa mites that were found dead on the bottom board of the hive, were studied in relation to the period the mites spent on adult honey bees, Apis mellifera L. (Hymenoptera: Apidae), prior to invasion into brood cells. The maximum period on adult bees was 23 days. To introduce mites, combs with emerging worker brood, heavily infested with mites, were placed into a colony and removed the next day. At the beginning of the first day following emergence from brood cells, 18% of the mites introduced into the colony was found on the bottom of the hive. Part of these mites may already have died inside the capped brood cells, and then fallen down after cleaning of cells by the bees. At the second and third day following emergence, respectively 4% and 2% of the mites on adult bees at the previous day was recovered on the bottom, whereas from the fourth day on only 0.6% of the mites on adult bees was recovered on the bottom per day. After invasion into brood cells, 8-12% of the mites did not produce any offspring. Of the mites that did reproduce, the total number of offspring was 4.0--4.4 per mite during one reproductive cycle, part of which may reach maturity resulting in 1.2-1.3 viable daughters, and 8-10% of the mites produced only male offspring. Reproduction was independent of the period the mites had spent on adult bees prior to invasion into brood cells.

Honey bee hygienic behavior and defense against Varroa jacobsoni

“…For example, previous studies have shown that young mother mites may not always reproduce in the first cell they enter, but may do so in subsequent cells (de Ruijter, 1987). Young mites that were not allowed sufficient time in the phoretic stage on adult bees before they were introduced may have delayed oviposition and lay fewer eggs (Beetsma and Zonneveld 1992; but see Boot et al, 1995). Also, the fertility of the mites decreased when they were introduced 24 h or more after the larval cell was sealed (Beetsma and Zonneveld, 1992).…”

Mortality of Varroa jacobsoni Oudemans during or soon after the emergence of worker and drone honeybees Apis mellifera L

“…A wire gauze prevented the bees from removing the mites from the sheet. Ruijter, 1987 (Liebig, 1994;Boot et al, 1995;Mar-tin, unpublished data) that suggested a strong correlation between levels of falling mites and the emergence of honeybee brood. The level of mite drop from naturally infested worker cells was nearly twice as high as that from the drone cells, despite drone cells being more attractive to the mite (Fuchs, 1990 (Martin, 1994) (Nation et al, 1992).…”

“…This relationship between development time of the bee brood and mite mortality had previously been suggested by Baggio (1994) (Martin, unpublished data). Various studies have found that 18% (Boot et al, 1995), 30% (Martin and Kemp, 1997) (Boot et al, 1995;Donzé et al, 1996) to around 0.8-0.9 mites per reproductive cycle in worker cells and from 2-2.2 (Martin, 1995) to 1.9-2.1 in drone cells.…”

“…Although the majority of the natural mite fall occurs within 2 days of brood emergence (Liebig, 1994;Boot et al, 1995) it remains unclear whether these mites arose from those dying within the sealed cells (Martin, 1994(Martin, , 1995 or shortly after bee emergence, when the mites often transfer between hosts (Kovac and Crailsheim, 1987; Le Conte and Arnold, 1987).…”

Stimulation of Varroa jacobsoni Oud. oviposition with semiochemicals from honeybee brood

“…Differences in the fertility seem to be related to either honeybee race or to the local strain of the mite [1,4]. It has been shown that reproduction of V. jacobsoni is influenced by factors acting during the phoretic phase [3,6,9,19,22] and during the first contact with the bee larva inside the brood cell [9,13,21]. In both cases, the factors acting on the mite are unknown.…”