Effect of mating frequency and brood cell infestation rate on the reproductive success of the honeybee parasite Varroa jacobsoni

Abstract

. The reproductve biology of Varroa jacobsoni, whose females infest honeybee brood, was studied in natural and transparent artificial brood cells. These investigations were made under the headings of maturation behaviour and fertilization, and the influence of infestation rate of brood cells on the number of mated females produced per infesting Varroa. Mating of Varroa daughters, observed in the transparent brood cells with time‐lapse video, occurs just after ecdysis and as soon as they arrive on the faecal accumulation prepared by the mother. Such females are remated for as long as no other freshly moulted daughter arrives on the faecal accumulation. The number of spermatozoa stocked in the spermatheca increases with remating, a strong indication for sperm mixing in this species when brood cells contain more than one Varroa foundress. The number of daughters per infesting mother decreases at higher rates of infestation per cell, but the proportion of such daughters with a mate rises sharply due to the higher probability of finding a male within multi‐infested cells. The number of mated daughters per mother is maximal in cells with two foundress Varroa females. The frequency distributions of infesting mites in drone cells are aggregated, and approximate to negative binomial distributions. We postulate from the above that the observed non‐random infestation by Varroa in drone brood augments the mite's mean reproductive success through the production of a higher number of mated daughters than the corresponding Poisson distributions would.

Comparative evaluation of sticky paper and hive debris as sampling methods for population assessment of Varroa destructor in Apis mellifera colonies

“…As brood area started expanding, favouring the entry of Varroa into brood cells as well as their reproduction, its population showed an increasing trend. These results corroborated the earlier studies that large number of sealed brood cells contributed to increase in mite population (Donze et al, 1996).…”

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

“…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between development time of the bee brood and mite mortality had previously been suggested by Baggio (1994) (Martin, unpublished data).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.…”

The invasive Korea and Japan types ofVarroa destructor, ectoparasitic mites of the Western honeybee (Apis mellifera), are two partly isolated clones

“…The adult male copulates repeatedly with each of its sisters (adelphogamy). However, two, or more rarely several, foundresses may lay eggs in the same cell (Fuchs & Langenbach 1989;Martin 1995;Donzé et al 1996). In that case, mating may occur between individuals of different lineages.…”