A survey on some factors potentially affecting losses of managed honey bee colonies in Luxembourg over the winters 2010/2011 and 2011/2012

Abstract

SummaryThe beekeepers of Luxembourg were asked for: 1. the honey bee (Apis mellifera) colony losses they experienced over winter; and 2. aspects of their beekeeping practice in May 2011 and 2012. Results on the magnitude of the winter losses in the managed bee colonies of Luxembourg are reported for the first time, and some factors potentially related to the losses such as varroa control methods, agricultural land use at the level of municipalities and the hive types employed were investigated. The number of managed honey bee colonies lost in Luxembourg was 938 out of 5,580 in winter 2010/11 and 1,172 out of 5,382 in winter 2011/12, corresponding to national loss rates of 16.8% and 21.8%, respectively. Elevated loss rates were observed in the Northern municipalities in both years. The losses reported from apiaries employing the hive types Dadant 10 or Dadant 12 were significantly lower compared to apiaries employing the hive type Deutsch Normal and losses with Dadant 12 were lower compared to hive type Alberti. Varroa control methods were grouped according to similarity concerning timing and treatment combinations. Differences of colony losses (%) between the four largest groups of similar treatment combinations were nonsignificant at P = 0.72, indicating that none of the most common varroa control method combinations reduced colony losses significantly below the average percentage of colonies lost per apiary. Evidence for an effect of the interaction between varroa control methods and hive type as well as for agricultural land use on colony losses is presented and discussed.