“…Several other variables are correlated with seasonal colony weight gain or honey production. These include colony population (Farrar, 1937;Szabo, 1982;Szabo and Lefkovitch, 1989), 24-h pollen collection (Szabo, 1982), area of sealed brood (Soller and Bar-Cohen, 1967;Szabo, 1982;Szabo and Lefkovitch, 1989), weight of bees in colony (Szabo, 1982), daily flight activity (Szabo, 1980), queen weight (Nelson and Gary, 1983), and several morphological characteristics (Milne, 1980(Milne, , 1985Milne and Pries, 1984;Szabo and Lefkovitch, 1988). Szabo (1982) (Laidlaw, 1987a, b) or isolated mating yards (Ruttner, 1988;Waller et al, 1989).…”