Varroa destructor detection in non-endemic areas

Abstract

Australia is one of the few countries where Apis mellifera are not infested by the parasitic mite Varroa destructor . In Australia a program called the 'Sugar Shake Team' has been implemented to detect an incursion of V. destructor , should it occur. The aim of this paper was to provide an estimate of the probability that V. destructor would be detected by the Sugar Shake Team program if an incursion had actually occurred (surveillance system sensitivity) using a scenario tree modelling approach. A secondary aim was to provide commentary on how surveillance for V. destructor incursions into Australia might be made more effective. Our analyses show that if one apiary in the study area was infested with V. destructor , there was only a 0.47% probability that infestation would be detected by the current program. We conclude that in its current form the Sugar Shake Team program does not provide protection to multi-billion-dollar beekeeping, pollination and agricultural industries in Australia. Surveillance for V. destructor can be made more effective by increasing the coverage and frequency of testing, deployment of additional sentinel hives and the use of sticky boards.surveillance / scenario tree / Australia / biosecurity / mites

Is testing the bee-all and end-all ofvarroaeradication?

“…Our modelling incorporates known varroa biology and hive testing practises to understand the dynamics of early outbreak spread of varroa between hives. In Australia, it is likely that varroa was not detected until 10-24 months after the first incursion (Department of Agriculture, Fisheries and Forestry 2011; Owen, Stevenson, and Scheerlinck 2021). In general, we are unlikely to know when the initial incursion occurs and we rely on positive detection in sentinel hives to trigger routine testing for varroa.…”

“…However, these studies have often focused on exploring how varroa or diseases travel through hives in a single apiary rather than through a naive population. In an Australian context, Owen et al study the potential spread of varroa mite following importation in Victoria, Australia (Owen, Stevenson, and Scheerlinck 2021). This studied how far varroa could spread in an naive population before interventions, such as testing, are applied.…”

Climatic predictors of prominent honey bee (Apis mellifera) disease agents:Varroa destructor,Melissococcus plutonius, andVairimorphaspp

“…Varroa has successfully become established in all continents where honey bees are maintained, and only a handful of island territories remain Varroa -free. 14,26 Many studies broadly highlight the impact of winter brood breaks on Varroa loads and differences in Varroa population growth in temperate versus tropical climates (reviewed in Rosenkranz et al 25 ). The studies that have investigated relationships with weather conditions have focused mainly on temperature, 9,22,23,27 with extreme heat being associated with reduced Varroa reproduction 22,23 but otherwise a positive relationship between Varroa occurrence and temperature has been observed.…”