New Publication on Preventing Pesticide Poisonings in Bees
In the wake of the pesticide poisoning of 50,000 bumblebees, The Pacific Northwest Extension Service has just published a revised edition of a pamphlet with information on protecting honeybees and wild bees from pesticide poisonings.
As we see from the excerpt below, there are a number of other ways bees can be poisoned by pesticides besides the obvious way of ingesting pesticides recently applied to blooms they pollinate.
The prevention of poisonings entails alertness, knowledge and care not only on the part of agricultural growers, but on the part of lawn care professionals and home gardeners.
My personal favorite (as you might guess!) on the list of ways growers can protect the bees essential to their crops is “Consider alternatives to pesticides.”
Below is some material from this publication:
Causes ofPoisoning in Pacific Northwest and California
Highly toxic insecticides with residual toxicity longer than 8 hours are responsible for most bee poisoning incidents reported on the West Coast, primarily those in the following chemical families:
■■Organophosphates (such as acephate, azinphosmethyl, chlorpyrifos, diazinon, dimethoate, malathion, and methamidophos)
■■N-methyl carbamates (such as carbaryl (or Sevin)
■■Neonicotinoids (such as clothianidin, imidacloprid, and thiamethoxam)
■■Pyrethroids (such as deltamethrin, cyfluthrin and Lambda-cyhalothrin).
Most bee poisoning incidents occur when:
■■Insecticides are applied when bees are foraging
■■Insecticides are applied to bee-pollinated crops during bloom
■■Insecticides are applied to blooming weeds in orchards or field margins
■■Insecticides drift onto blooming plants adjacent to the target crop
■■Bees collect insecticide-contaminated pollen (such as corn), nectar (such as cotton or mint), or other materials from treated crops that do not require bee pollination
■■Bees collect insecticide-contaminated nectar from plants treated with systemic pesticides
■■Bees collect insecticide-contaminated nesting materials, such as leaf pieces collected by alfalfa leafcutting bees
■■Bees collect insecticide-contaminated water (from drip tape or chemigation, for example)
■■Beekeepers and growers do not adequately communicate
isn’t always obvious
Delayed and chronic effects, such as poor brood development, are difficult to link to specific agrochemicals, but are possible when stored pollen, nectar, or wax comb become contaminated with pesticides. Severely weakened or queenless colonies may not survive the winter.
Beekeepers may request a laboratory analysis of dead bees to determine if pesticides were responsible for an incident. State agriculture departments in Oregon, Washington, and Idaho, and the pesticide regulation department in California, investigate suspected bee poisoning incidents (see original document for contact information).
Thanks to all of you who are helping care for our pollinators with your personal choices!