We expected to demonstrate improvements in honey bee colony health and strength through using a middle entrance.
By relocating the hive entrance from the bottom of the hive to above the brood nest, we expected to reduce the population of Varroa mites in the hive. Mites do fall off bees, but in a typical hive, they land on the bottom board, and may catch a ride back into the brood nest on another bee. By putting an entrance above the brood nest there will be fewer free rides. We also added in measuring the effects of solid and screen bottoms as variables. Thus, the treatments were:
Solid bottom, bottom entrance – the standard hive
Screen bottom, bottom entrance – typical mite control
Solid bottom, middle entrance
Screen bottom, middle entrance
We monitored 20 new colonies for one year, measuring the Varroa population using the 24hr natural fall method, and hive weight, to assess the comparative efficacy of a middle entrance as a mite control alternative.
The summer mite count difference between solid bottom and screen bottom hives is statistically significant in this experiment. Other variations were not.
Winter survival seems to be reduced with middle entrances.
Spring buildup seems to be earlier with solid bottom hives and bottom entrance hives for weight gain and mite numbers.
Weight gain seems to be increased with middle entrances.
The mite fall rate in winter is so low that using a screen bottom during winter is unlikely to have any benefit. Mites that land on the bottom will likely perish from the cold long before they find a way back to the bee cluster.
For complete final report, open file below.
This is a proposal to continue SARE FNE08-646 for a second year, as the fall of a second year is when Varroa mites have had enough reproduction time to cause significant problems for the honey bee.
We expect to demonstrate improvements in honeybee colony health and strength through using a middle entrance for the beehive.
By relocating the hive entrance from the bottom of the hive to above the brood nest, we expect to reduce the population of Varroa mites in the hive. Mites do fall off bees, but in a typical hive, they land on the bottom board and may catch a ride back into the brood nest on other bees. By putting an entrance above the brood nest there will be fewer bee rides.
We have established 20 colonies in July 2009 with different hive configurations and have been monitoring hive weights and 24 hour Varroa drop rates bi-weekly. Theses hives required constant syrup feeding through to October to prepare for winter and weight gains were generally even. The feeding method was to place the syrup in accessible containers in each hive. Variations due to entrance location would not be expected to affect weight gain rate as much as when the bees are foraging for nectar.
Varroa drop rates indicated a very low but increasing mite load which is consistent with newly established colonies. We expect that next fall the Varroa mites will have had a whole season to multiply and become a problem to the honeybees and the advantages of different hive configurations will be more observable.