12.6.2. Example 2: Acute effects of sublethal doses of insecticides or acaricides on foraging
To investigate whether the acute oral administration of insecticides or acaricides alters foraging parameters
1. Use queen marking tubes (Fig. 24B) for catching foragers.
2. Tag foragers with an RFID transponder (see section 11.2.3.).
3. Release bees to forage freely until the next day.
4. On the following day, catch previously tagged bees at the feeder entrance and identify them with the USB-Reader-Pen (iID® PEN mini USB, microsensys, Erfurt, Germany) directly after landing (for this, the feeder needs to be removed from the feeder compartment).
4. Allocate the tagged bees to different experimental groups.
5. Dissolve the substance (insecticide or acaricide) in sugar solution.
6. Offer the substance solution to the treated group in a cap removed from a 1.5 ml Rotilabo® micro centrifuge tube (Carl Roth GmbH, Karlsruhe, Germany), embedded in the foam plastic of the plunger of the queen marking tube.
7. Offer a control sugar solution containing an equivalent of the solvent (if any is used) to the control group in the same manner as described in step 5.
8. Keep bees isolated in the marking tubes for approx. 20 min to avoid trophallaxis with other bees and observe potential regurgitation.
9. After the treatment, the bees can be released at the feeding site or into the registration hive.
10. Determine their subsequent foraging activity for any desired experimental period.