EXPERT REACTION: Can banning household pesticides save bees?

As well as any intrinsic value that we might attach to them, honey bees are important contributors to agriculture and horticulture because of their ability to pollinate flowers. Although honey bee populations are stable in Australia, they have declined in some regions in the northern hemisphere.  Apart from broad-scale influences on the population of any natural species, such as climate change and habitat modification, one definite cause of the decline (the Varroa mite) is known, and members of one class of pesticides are under suspicion. There is no doubt that these pesticides, of the neonicotinoid class, are toxic to honey bees (and possibly other species, too). However, the distribution of the pesticides and the extent to which honey bees are exposed are difficult to assess. Hence we have suspicion, but not proof, of widespread harm. Coming on top of other threats, even a small contribution from the pesticides may be enough to tip the balance in some communities of honey bees. But ... read on.

Stringent biosecurity in Australia has kept the mites out, and whatever influence there is from the neonicotinoid pesticides has not been great enough to affect our honey bee populations. Our regulatory agency, the Australian Pesticides and Veterinary Medicines Authority (APVMA), has studied the situation carefully, with a major report in 2014 and an update this month (https://apvma.gov.au/node/28786). They conclude that we don't have a problem ... but they are keeping an eye on developments.

The use of neonicotinoid pesticides has been restricted in Europe, but some of these substances can be used here under conditions prescribed by APVMA as part of their pre-registration assessment. None of these pesticides has been detected in the annual surveys of chemical residues on animal and plant products in Australia.

Domestic use of such pesticides is on a tiny scale, and any impact from such use would be dwarfed by broad-acre applications in fruit and vegetable producing areas. Why then would Bunnings remove them from sale in Australia and the UK? The answer might be a petition signed by concerned people who oppose the use of these pesticides.

There has been a growth in pressures on retailers to stop selling products that pressure groups don't like. Stores like Walmart (in the US) have responded by removing some products from their shelves. People who sign petitions of this sort will no doubt believe that they are doing the right thing by 'cherry picking' this month's substance of concern, even when the product has the approval of careful (and well-qualified) regulators. It's a lazy response, however. The idea that there would be any gain for the honey bees is probably illusory. But of course, Bunnings will get some 'brownie points' for doing not much, while burnishing its green credentials. It will be interesting to see if other retailers follow suit.

Neonicotinoids are extremely toxic to bees and very persistent in plants. They end up in pollen and nectar, which are collected by bees, as this is their only food. Depending on the dose, the treated plants can stay toxic for months or even years. I have had bees dying in a greenhouse when they foraged on plants that had been treated with Confidor, at the recommended dose, ten weeks earlier.

Home gardeners often benefit from native bees as they pollinate their fruit and vegetables, such as tomatoes.

In my view, home gardeners shouldn’t be given the option of making the plants in their garden toxic to bees. Therefore, I am very supportive of Bunnings' and Mitre 10's decision to withdraw Confidor from their shelves and hope other companies will follow suit.