As featured in the Tasmanian Country publication 26th August 2022
Now more than ever, with the imminent threat of Varroa destructor on our shores, farmers and beekeepers need to collaborate to ensure the safety of bees as spring and summer get underway.
An increase in the number of managed hives available for crop pollination is crucial to the continued prosperity of the Tasmanian agricultural and horticultural industries.
Although Tasmania remains free from the tiny but devastating varroa mite, its incursion into New South Wales has seen biosecurity protocols tighten.
Local beekeepers can no longer import new queens into the state. This means beekeepers who provide crucial pollination services will be even more conscious of protecting their beers from pesticide poisoning this season.
Many chemicals used to control insect pests are toxic to honey bees.
Agricultural chemicals vary in their toxicity and the conditions under which they are toxic. Some kill bees on contact, others are only mildly toxic, some lose their toxicity quickly after application, while others are safe when they are dry.
Faced with a large array of chemicals, the best way to avoid poising bees is to avoid applying toxic chemicals to flowering crops and pastures that are likely to be visited by bees. Of course, this approach is easier said than done.
To reduce the risk of poisoning honey bees when spraying, it also helps to understand when and how poising can occur.
When chemicals are applied directly to a flowering crop, foraging worker bees are exposed to contaminated nectar, pollen or water. These forages carry the contaminated nectar, pollen or water back to the hive, contaminating the entire colony.
A similar risk is present when applying chemicals to non-flowering crops that contain flowering plants (e.g. weeds).
It is important to note that one of the most common causes of bee poising is spray drift, where a pesticide or other chemical has been applied to a crop that is not in flower but has drifted on to flowers of other plant species.
It is critical to only carry our spraying operations under suitable conditions. Spraying during a temperature inversion can not only put bees at risk, but also can impact other agricultural and horticultural crops. Fine spray particulars can drift long distances during an inversion.
It is incumbent upon farmers to contact the owners of any hives in the area well before spraying, so beekeepers have an opportunity to relocate or protect their hives.
Consider the owners of hives on adjacent properties, bearing in mind bees commonly forage within a 5km radius, sometimes further.
Of course, communication is a two-way street and beekeepers also are obliged to notify neighbouring growers when placing their bees at a new location.
Consider adopting integrated pest management (IPM) principles where appropriate. Of course, this has the added benefit of reduced input costs as chemical prices soar.
When spraying is unavoidable, talk to your agronomist and beekeeper to select chemicals that pose a low risk to bees, but will still achieve your required outcome.
If using spray contractors, inform them of the location of any hives that could be affected and ensure they understand the importance of reducing the risk of honey been poising.
A handy one-page Pesticide risk management plan can be downloaded for free from https://beeaware.org.au
Work with local beekeepers to implement this management plan and remember – posing bees reduces future pollination potential, which impacts yields and profits.