BACKGROUND

The detection in early 2003 of Varroa destructor, a parasitic mite of the honey bee (Apis mellifera), prompted a request from the Barbados Ministry of Agriculture and Rural Development for technical assistance to advise Ministry entomologist Ian Gibbs and commercial beekeeper Rudy Gibson. Although only recently identified in Barbados, apparent losses of domestic bee hives and wild feral colonies had become epidemic since starting in approximately 2000, according to anecdotal reports. It is estimated that about 75% of the honeybee population on the island was destroyed, an effect commonly associated with Varroa introductions worldwide along with the resulting lowered honey production as well as diminished pollination potential for agricultural crops.

FINDINGS

A mite survey was conducted during the consultant’s Dec.6-15 visit, inspecting over 50 beehives in the parishes of Christ Church, St. Michael and St. Andrew and also examining wild/feral colonies in Bridgetown. Varroa was found in all locations indicating widespread distribution, however the phoretic infestation levels in samples analyzed in the laboratory were low (<5%) and the overall conditions of survivors suggests that host/parasite coevolution has progressed from the acute/virulent phase to the chronic/tolerant stage. Given that observed colony pathologies in the field were relatively minor in scope (chalkbrood/sacbrood, paralysis/deformed wings) for what is termed “parasitic mite syndrome”, the survival rates of both domestic and feral populations appear to be on the rebound. Some colonies demonstrated considerable defensive behaviour, which may be related to particular environmental stresses (such as drought/nectar dearth) and/or stock genetics issues (including introgression/mongrelization).

ACTIONS

Mitigation by using the miticide Apistan (fluvalinate) strips provided by the Ministry was enacted by the beekeeper at this time as a prophylactic measure, although mite levels may be below usual action thresholds associated with integrated pest management. One apiary was to be left untreated as a comparative test in order to asses natural susceptibility of surviving stocks, with the intent that non-chemical control strategies be employed in the future to prevent development of pesticide dependence/resistance/contamination.

RECOMMENDATIONS

Suggest continued regular monitoring of varroa levels in domestic/feral bee populations to attempt identification of effective integrated pest management methods, including screening for genetic diversity and disease prevalence as well as exotic pest introductions. The development of apicultural training programs for both new/old beekeepers and public service personnel should be a priority for government and international agencies, with the hope of rebuilding the industry.