Submitted to: Proceedings of Apimondia Congress
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2007
Publication Date: N/A
Technical Abstract: African bees are known to preferentially remove brood that is infested with small hive beetles (SHB). European honey bees (EHB) also remove infested brood but at a lower frequency. The response of different stocks of EHB to brood infested with SHB has not been studied. Therefore, this study was conducted to compare the removal response of Russian (n = 12) and Italian (n = 12) honey bees against brood infested with SHB. SHB-infested brood was obtained as described by Ellis et al. (2003). For analyses, brood cells in each of the treated and control sections were grouped as follows: a) NPNS = no perforation on capping and cell wall; b) NPWS = with cell wall perforation only; c) WPNS = with capping perforation only; and d) WPWS = with capping and cell wall perforations (de Guzman and Frake 2006). Brood removal was assessed 2, 4, 6 and 20 h after the brood frames were returned to their respective colonies. Our results showed no significant interactions (P=0.942) among bee stocks, treatment group and time of observations for the percentage of brood removed. However, significant interaction between treatment group and time of observations (P<.0001), treatment group (P<.0001) and time of observations (P<.0001) were detected. The two stocks were comparable (P= 0.819). Analyzing only those brood with perforations (NPWS, WPNS, and WPWS), Italian and Russian bees displayed removal rates of 59.66±3.88% and 60.31±3.76%, respectively. These rates were similar to the findings of Ellis et al. (2004) for EHB (57%). However, SHB lays eggs mostly by puncturing the sides of capped brood via neighbouring empty cells. Thus when NPWS and WPWS only were analyzed, higher rates (Italian = 75.83± 3.35%, Russian = 75.98±4.04%) were obtained. These rates were higher than the rates observed by Ellis et al. (2004) even in Cape bees (67%). Overall, the NPWS group had 74.99±5.39% brood removal. This high removal of brood having cell wall perforations only may indicate an increased ability of both Italian and Russian bees in detecting SHB’s presence inside the capped brood, resulting to complete brood removal. The importance of this behaviour in the regulation of SHB population in bee colonies will be discussed.