Natürliche Verteidigungsmechanismen der Honigbiene gegen die Varroamilbe
Wild honey bee colonies—both truly wild (in trees and buildings) and simulated wild (in smallhives)—were studied to determine their life-history traits, to see if these traits have changed now that these colonies are infested with Varroa destructor . Most colonies (97%) survive summers, but only 23% of founder (first-year) colonies and 84% of established colonies survive winters. Established colonies have a mean lifespan of 5–6 years and most (87%) have a queen turnover (probably by swarming) each summer. A population model shows that these life-history traits produce a stable population of colonies. Remarkably, the suite of colony life-history traits found in the 2010s (with V. destructor ) matches that found in the 1970s (without V. destructor ). It seems likely that the wild colonies living near Ithaca, NY, possess defenses against V. destructor that are not costly.