BEHAVIORAL-ATTRIBUTES AND PARENTAL CARE OF VARROA MITES PARASITIZING HONEYBEE BROOD

Varroa jacobsoni, an ectoparasite of the Asian honeybee Apis cerana, h as been introduced world-wide, and is currently decimating colonies of the European honeybee Apis mellifera. Varroa's reproductive cycle is tuned to that of drone cells, those mainly parasitized in the original host. We describe here how a single fertilized female, infesting a br ood cell, can produce two to four adult fertilized females within the limited time span of bee development (270 h in worker and 330 h in dro ne cells), despite the disturbance caused by cocoon spinning and subse quent morphological changes of the bee. From observations on transpare nt artificial cells we were able to show how the mite combats these pr oblems with specialized behaviors that avoid destruction by the develo ping bee, prepares a feeding site for the nymphs on the bee pupa, and constructs a fecal accumulation on the cell wall which serves as a ren dezvous site for matings between its offspring. The proximity of the f ecal accumulation to the feeding site facilitates feeding by the matur ing progeny. However, communal use of the feeding site leads to compet ition between individuals, and protonymphs are most disadvantaged. Thi s competition is somewhat compensated by the timing of oviposition by the mites. Use of a common rendezvous and feeding site by two or more Varroa mothers in multiinfested cells may have developed from the pare ntal care afforded to them as nymphs.