188.8.131.52.2. Collecting bees for use during the study
This topic is reviewed in detail in Williams et al., 2013.
1) The most accurate method of collecting the bees is to put them singly, at the dispenser, into glass test tubes with a diameter greater than 1 cm and 10 cm in height (Falcon vials).
2) The collection can be accelerated by the use of the end section of an “insect vacuum” (Fig. 4).
3) For safety reasons, the vacuum necessary to suck a bee into the tube can be provided by an electric pump. If done manually, a fine, soft mesh should be placed at the mouth of the insect vacuum and a second protective diaphragm over the mouth of the test tube. This should be a thin, fine mesh.
4) It is necessary to limit captured bee exposure to any sort of rubbery material where they could insert their sting and die.
5) If it is not necessary to capture the bees singly at the dispenser (for example in the free flight trials), the bees may be caught en masse in a 20 cm tulle cage (or similar), placing it at the entrance to the hive (Fig. 5) (section 184.108.40.206 in Williams et al., 2013).
6) The dispenser should be withdrawn from the cage, the cage closed and taken to the laboratory.
7) At the laboratory, the bees may be fed with honey placed on the upper part of the cage (Fig. 3).
8) The bees may be transferred from the cage to be kept singly in the laboratory, as described for the capture at the dispenser (step 1 above).
9) It is ideal that the bees not used at the end of the trial be freed to be renewed on successive days of experimentation.
10) Wherever possible, the powdering trials should be conducted using bees collected at the dispenser, avoiding using bees collected with an entomological net in front of the hive. This ensures that no juvenile bees are captured and used during the study.
11) If necessary, in the winter, bees can be caught
in front of the hive, taking care to catch those bees returning to the hive
(thus, certainly foraging worker bees) and not those exiting the hive who could
be solely engaged in orientation flights. Nevertheless, it should be
noted that winter bees
normally should not be used for standardized ecotoxicological testing.
Fig. 4. Insect vacuum (aspirator) used to capture the bees. The two mesh diaphragms safely prevent the bee from being sucked into the mouth of the operator.
Fig. 5. Capture of bees from the hive. Method described in section 220.127.116.11 in Williams et al., 2013.