2.4.2. Traps in colonies
Several devices to trap adult SHB inside colonies are available. All of them have entrances which allow SHB to enter but exclude honey bees. Most of these traps use mineral or vegetable oil as a killing agent. There are traps available for all positions in the hive: under the bottom board, on the bottom board, in the frame, as a replacement for a frame, between frame top bars, and at the entrance of the hive. Two very similar devices that are widely used are the “Beetle Eater®” and the “Beetle Blaster®”. Both are designed to be placed between two frame top bars either in the bottom chamber or in supers. Most of these in-hive trapping-devices are designed to kill SHB and only allow an approximately measurement of the SHB infestation rate of colonies. For collection of live SHB for laboratory studies, we recommend a very simple method to catch adult SHB inside of the colonies using diagnostic strips (Schäfer et al., 2008; 2010a). These devices are made of corrugated plastic (75×500×4 mm) strips which create rows of narrow tunnels for SHB to hide in, but prevent access of bees. Diagnostic strips have a mean capture efficacy of 30% of the colony SHB population, and provide a fast, cheap, and easy quantitative diagnosis for estimating SHB population sizes in the field (Schäfer et al., 2008). Furthermore, in light of the very efficient detection rate (96.3%), these diagnostic strips are also a suitable tool to screen colonies in areas, where SHB have not been reported yet (Schäfer et al., 2010a). This will foster a fast sanitation response to prevent SHB spread given accidental introductions. Please refer to the Portugal case for successful prevention of SHB spread (Murilhas, 2005) and to Australia/USA for consequences of too late detections (Neumann and Ellis, 2008). Usage is as follows (Schäfer et al., 2008; 2010a):
1. Place one diagnostic strip on the bottom board of a colony by sliding it through the flight entrance (Fig. 7).
2. Leave the strips in the hives for two nights to provide SHBs time to find the refuges.
the strips by pulling them out quickly and shake the enclosed SHBs into bright
trays for counting or for collection with an aspirator or other suction devices
(see section 2.4.1.).
Fig. 7. Usage of diagnostic strips to detect adult small hive beetles. The strips are placed on the bottom board of a hive by sliding it through the flight entrance. Special care must be taken that the bottom boards are clean and even to avoid SHB hiding underneath the strips and not inside. Photo: USDA.