This forces the colony to forage early, and especially if unfavorable weather conditions prevail, and leads generally to premature heavy forager loss. These conditions become most important in temperate climates, Mr. Horn says, when regular cold spells can occur after long warm periods. Due to weaknesses in the colony from premature brood rearing, the endemic disease parasite Nosema apis can easily gain the upper hand. Other disease vectors may also cause serious damage. The wire mesh floor guarantees a constant exchange of air, and heat build up due to direct sunlight on the hive wall is unlikely to result in premature brood production.
Brood rearing only begins in earnest when the weather begins to be warm for lengthy periods.
Because of this, colonies are able to exploit early nectar flows in an optimal manner. Over wintering colonies in hives with open floors, according to Mr. Horn, when compared to those on solid floors, offers another positive advantage. Due to the constant exchange of air only moderate condensation occurs. Thus, fungal formation on the outside of combs does not occur as happens in colonies over wintering in hives with solid floors. . Although temperate zones are emphasized in Mr. Horn's paper, those in more tropical areas may also benefit from ideas presented here.