A study has found use of the protein-based Vespex wasp bait for control of German and common wasps does not harm bee colonies.
Vespex wasp bait is an important wasp control tool for beekeepers to protect their bees from introduced wasps stealing honey and attacking bees. It is also used by community groups, the Department of Conservation (DOC) and others where wasps are a nuisance to people and to protect native birds and insects from wasps.
In the Victoria University of Wellington and DOC study, no fipronil insecticide used in Vespex wasp bait was detected in a total of 480 worker bee, bee larva, honey and pollen samples collected over a two-year period from 30 hives which had wasp bait stations nearby.
The study was carried out by DOC scientist Eric Edwards and Victoria University of Wellington scientists Ethan Woolly, Rose McLellan and Dr Robert Keyzers.
Eric Edwards says Vespex wasp bait was considered safe for bees as it’s made from protein with no sugars and the research adds further weight to confirm it being unattractive to bees as they prefer sweet foods.
Testing of samples of bees, bee larvae, pollen and honey was carried out at the Victoria University of Wellington School of Chemical and Physical Sciences.
Dr Rob Keyzers says the test that was developed was sufficiently sensitive to be able to detect very small traces of fipronil, matching sensitivities reported in European field studies for agricultural uses of the insecticide and for laboratory testing of toxicities for bees.
A low level of a fipronil breakdown product was detected in initial testing of seven worker bees, but it wasn’t detected in two further tests of the same bee sample. The researchers concluded the derivative trace was likely just from a single bee and a rare occurrence given it wasn’t detected in follow up testing from the same sample or from any other hives sampled and it may not have come from Vespex wasp bait.
“Bees are social insects that share resources within their hives,” says Eric Edwards. “Foods are rapidly transferred within a hive environment between forager and nurse bees, bee larvae and products like honey. All of these were tested showing no evidence of transfer inside hives of the insecticide in the wasp bait.”
An economic impact analysis published in 2015 estimated $8.8 million in direct costs to beekeepers from wasp attacks with even higher costs from the impact on the services that bees provide.
The research report has been published in the PLOS ONE open access scientific journal published by the Public Library of Science (PLOS). It can be found at https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0206385
Source: Department of Conservation