Testing with Bees now available year-round in Australia
The determination of acute toxicity to the European honeybee Apis mellifera may be required in the evaluation of toxic characteristics of substances when exposure of bees and other beneficial insects to a given chemical is likely. These tests have however been restricted to around the Northern Hemisphere summer season, when the bees are active and breeding. Now that ESI offers GLP recognised ecotoxicity testing services from temperate Australia, we are able to complement the existing honeybee testing services by offering tests over the approximate 6-month period when these tests cannot be performed in Europe or North America. The European honeybee produce brood all year-round in parts of temperate and Northern Australia, allowing testing to be performed at any time.
Ecotoxicity Tests Available
There are two acute toxicity tests available based on the OECD test guidelines 213 and 214: The Oral toxicity test and the Contact toxicity test. For both tests, adult worker bees are exposed to a range of doses of the test item for 48 hours, at 25°C ± 2°C. For the oral toxicity test, the test item is administered to the bees via a glucose solution that is fed to them for a maximum of 6 hours. The bees are then fed the same diet, free of the test item, for the remainder of the exposure period.
For the contact toxicity test, the bees have first to be anesthetised using carbon dioxide (CO2) gas. The test item is then applied directly on the thorax of the bees, using a micropipette. At the end of the exposure period, the number of surviving bees is counted.
Statistical analyses are then applied to the test data to determine the concentration of the test item causing 50% mortality in the test population (LC50). The test data can then be used to estimate the concentrations of the test material likely to cause acute toxicity in the field.
Our bee hives are located in natural forest in Wedderburn, in temperate South-Western Sydney, New South Wales. These forests are dominated by various Eucalyptus species (red gum, scribbly gum and iron-barks) and a diverse understory with species flowering at different times of the year. This diversity provides our bees with pollen and nectar from different species over each season, providing the best environment and conditions for the bee colonies to flourish. This spring, our bees are visiting flowers of Boronia (Rutaceae), Grevillea (Proceaceae), Kunzia (Myrtaceae) and Leptospermum (Myrtaceae), which is producing a fragrant pale-amber honey similar in tone to the famous leatherwood honeys of Tasmania. Summer will bring many of Eucalypts to bloom, which will change the flavour of the honey produced. The absence of the Verroa mite from Australia (the only place to have avoided this catastrophic parasite) means that our bee hives are not treated with any chemicals or pesticides.
Both the Oral and Contact honeybee acute toxicity test complement the package of GLP recognised tests that ESI offers. Please email firstname.lastname@example.org for further information.