Apidologie (1999) 30, 383-395

Keith S. Delaplane and W. Michael Hood (1999)
Economic threshold for Varroa jacobsoni Oud. in the southeastern USA
Apidologie 30 (5), 383-395
Abstract: This research was designed to determine economic thresholds for Varroa jacobsoni mites in mature overwintered colonies under conditions that encourage or discourage mite immigration. Congruent data from the present study and our earlier work suggest that a true late-season (August) economic threshold for mites in the southeastern USA lies within a range of mite populations of 3172 - 4261, ether roll mite levels of 15-38, and overnight bottom board insert mite levels of 59-187 in colonies with bee populations of 24808 - 33699. Overwintering colonies can benefit from an additional early-season (February) treatment. This benefit was realized in colonies which in February had the following average values: mite populations 7-97, ether roll 0.4-2.8, bottom board inserts 0.6-10.2 and bee populations 12606-13500. Continuous acaricide treatment never achieved colony bee populations or brood number significantly higher than in colonies treated more conservatively. There is evidence that minimizing mite immigration has the benefit of delaying the onset of economic thresholds.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Varroa destructor		U.S.A. (SE)