Zika and Pesticides

Honey bees are collateral damage in the war on Zika.

Bee kills from pesticide treatments are not new. What is new is a rational fear of the Zika virus and the rapid growth in commercial mosquito abatement franchises that feed on that fear. Many of these companies spray and fog at all hours of the day, in all wind conditions, and use pesticides that are highly toxic to honey bees and other beneficial insects and aquatic life.

To reverse this trend, beekeepers need to communicate to neighbors and elected representatives that there are better ways to fight Zika than the scorched earth policy of indiscriminate fogging and aerial sprays. Zika is a scary virus that causes birth defects. Any attempt to minimize that threat may end any productive dialog with a neighbor. Instead, beekeepers need to become better communicators, better entomologists, and better pesticide experts than the guy that drives a mosquito control panel truck.

A rapidly growing trend

Failing to take an active role in mosquito control education means abdicating that role to mosquito control companies that are disinclined to protect honey bees, beneficial insects, and aquatic life. Lacking better information, more households will sign abatement contracts with pest and mosquito control companies. There will be more drift of deadly pyrethrin clouds and more heartrending bee kills.

Knowledge is our weapon. Share it with your neighbors. It wouldn’t hurt to also share a bottle of local, pesticide-free honey as well.

Read more about pesticides used for mosquito control here.

Zika virus is a flavivirus, related to yellow fever, West Nile, and dengue. There are no vaccines to prevent Zika or medicine to treat the infection. Zika is transmitted primarily by Aedes species mosquitoes that bite during the day and night. Infection during pregnancy can cause congenital brain abnormalities, including microcephaly to the unborn child.

Learn more:

Yes and no. As of March 2, 2017, there are 116 confirmed travel-related cases of Zika in Georgia. These are cases of people returning to Georgia after having contracting the virus outside of the state. There has never been a case of locally‐transmitted Zika virus reported in Georgia as of August 2016. Local transmission means that local mosquitoes have been infected with the virus and are spreading it to people in the area.

Zika is transmitted mostly by the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus). The Asian Tiger mosquito (Ae. Albopictus) is found throughout the state and bites during the day. Zika is also potentially spread by humans through sexual activity, blood transfusion, and from a mother to her unborn fetus.

Since there are currently no cures or vaccines for Zika, it is important to avoid Zika:

  • Reduce the mosquito population (see section below)
  • Reduce the likelihood of mosquito bites (see section below)
  • Avoid travelling to areas with Zika outbreaks. This includes most equatorial countries, south Florida, and Brownsville, Texas. (see CDC Travel Information)
  • Avoid sexual intercourse with individuals from Zika outbreak areas
  • Add a fan to the porch. Mosquitoes are weak fliers and cannot navigate in a fan-induced wind. If you eat outdoors, a fan above and a small alternating fan on the floor will protect you above and below the tabletop.
  • Repair small holes in door and window screens.
  • Use a mosquito repellent such as DEET or Picaridin. Alternatively, Oil of Lemon Eucalyptus and IR3535 are biopesticide repellents made from natural materials.
  • Pregnant women should wear lightweight long sleeves, pants, and socks when outdoors.
  • Reduce mosquito populations – see next section.
  • Avoid puddles and standing water no matter how small.
  • Pick up toys, cups, bottles, or other yard clutter that might retain water.
  • If you have a bird bath, wading pool, or small water feature, try adding a mosquito dunk. Each dunk contains a bacteria, Bti, that is harmless to humans and bees but deadly to mosquito larvae. Alternatively, change the water once a week or add a fountain to keep the water moving.
  • Clean out rain gutters so that rotting leaves do not dam up water.
  • Stock permanent water pools, such as ornamental ponds, with mosquito larvae eating fish such as Gambusia
  • Drill drain holes in old tires. Add drainage ditches to prevent standing water after rainstorms.
  • Put up bat boxes. A little brown bat – the most common bat in Georgia – can consume about 600 to 1,000 mosquitoes in an hour. A nursing little brown bat mother may consume as many as 4,500 mosquitoes in a single evening – more than her body weight in insects. We are lucky to have lots of these bats in our area. Look up in the sky at dusk and you will see bats feeding on mosquitoes. Unlike pesticide applications, bats are free and they work to reduce the mosquito population every night.
  • Mosquitoes hang out in tall grass during the day so keep weeds trimmed and cut grass often.
  • Frogs help keep mosquito populations in check. For more info on making your property frog friendly, go to amphibianfoundation.org

Some homeowners (and mosquito control companies) are going to spray. Period. We are all better off if applicators are knowledgeable in the correct way to select and apply insecticide.

  • Avoid spraying flowers in full bloom.
  • Apply pesticides after sunset or before sunrise. Bees do not fly in the dark.
  • Avoid aerial spraying or fogging. But if you must, do not spray or fog during windy conditions. Optimally, apply the pesticide directly to the ground using a low pressure, large droplet sprayer. This greatly reduces the drift of pesticide off of your property.
  • Know that some pesticides are less harmful to honey bees and beneficial insects. The pdf at Less Toxic Insecticides provides useful information on the selection of pesticides.
  • Avoid pesticide formulations of dust or wettable powders which are similar in size to pollen grains. Instead, use granulars, solutions, or soluble powders.
  • Spray lower limbs of shade trees, shrubs and other non-flowering plants to reduce adult mosquito population. Bees do not frequent those locations but mosquitoes do.
  • Understand that in addition to gathering nectar and pollen from flowers, bees also gather water in the summer as a means of reducing temperature inside the hive. If a bee-deadly pesticide gets into water, it is likely to be collected by a honey bee.
  • Please notify local beekeepers before a pesticide is to be applied. They can cover their hives with drop cloths. That will help protect the colonies from drifting pesticide but know that pesticide applied to flowers in full bloom is likely to end up in bees and spread to other bees in the hive. Beekeepers can also change the water source that they provide for bees.
  • Please use pesticides that have the shortest persistence in the environment.
  • Know that mosquito treatment companies typically use pesticides from a group of chemicals called pyrethroids that are promoted as being safe and natural. They are – to humans – but these pesticides are highly toxic to pollinators and other beneficial bugs, fish, and small aquatic organisms.
  • Understand that the benefits and dangers of pesticides, as represented by commercial mosquito treatment companies is often at odds with information published by evidence-based government and university research centers.
  • If you must spray, spray only as needed. Contract spraying on a predetermined schedule wastes pesticide and money and may contribute to pesticide-resistant mosquitoes.

Every time a news story covers the Zika, West Nile or some other mosquito-borne virus in the US, phones start ringing at pest and mosquito control companies. In the mind of most homeowners, calling a mosquito control company is the most rational response. A panel truck shows up – at any hour of the 9-5 work day – and workers starts fogging the yard with pyrethrins. If the company is lucky, they will sign a recurring contract that guarantees multiple visits.

Pyrethrins are relatively safe to vertebrates but deadly to invertebrates such as honey bees, native pollinators, and dragonflies (that eat both mosquito larvae and mosquitos). A cloud of pyrethrin can drift into an apiary or – if sprayed on flowers – toxic nectar and pollen can be carried back to the hive.

Cultural Approaches

Bee kills are difficult to prevent unless you have neighbors that are educated in alternatives to fogging and are willing to work with you and inform you of sprayings.
In the summer of 2016, I lost all my hives to single pesticide event. In the Spring 2017, I assembled the following into a gift bag and gave it to each of my five nearest neighbors. The response from my neighbors has been very positive. They are now armed with knowledge and have a vested interest in protecting beneficial insects. Tom Rearick, MABA member & Master Beekeeper

Tactical Approaches

If you know that a spraying is going to occur, you must protect your bees from drift and from flowers and water that were sprayed.
  • Minimize effects of pesticide drift. These techniques will only work if you are warned ahead of time.
    • Determine if your hives are downwind from the spraying
    • Move the hives to a safe location if practical
    • Cover the hives with a breathable ground cloth and wet it down to cool the colony.
    • Change water sources that were exposed to drifting pesticides
  • Minimize effects of toxic forage and poisoned water.
    • Run sprinklers or misters to keep foragers in their hives. They will forage less if they think it is raining.
    • Change the water that you provide to bees.
If I knew that flowers in full bloom were being sprayed and my hives were not downwind, I would immediately dump honey into a pan and set it out in the apiary. The bees would find it and prefer it to other potentially toxic nectar sources. Open feeding is usually a bad idea because of the possible transfer of disease but that risk is much smaller than a known pesticide spray. This approach might work for a day in a small apiary but that may be all you need because many pesticides break down in sun and air. At any rate, the pesticide is less potent after 24 hours. Diluting the honey with water might make it last a little longer. If you lack the honey, you could make a cane sugar syrup. Tom Rearick

If a colony has lost most of its foragers but is stable after a day and still has plenty of honey and pollen, it has a good chance of surviving on its own. Move the surviving hive to a less toxic location with clean forage if possible. If you cannot move the hive or if there is insufficient forage, provide honey or sugar syrup. Provide clean water. The queen may stop laying for awhile but should resume. If she does not resume laying in a week or so, replace her.

However, if bees continue to die, there is most likely toxic pollen and nectar in the hive. The bees will continue to die until they are separated from the now toxic pollen and nectar. Shaking bees into a clean hive followed by a feeding may save them. Wax foundation that has absorbed pesticide cannot be rinsed out – it should be destroyed.

How to Report Bee Kills

The experience of finding your bees dead in piles is devastating. One tempting response is to withdraw from a hobby that causes such a painful experience. Another response is to recognize that – as stewards of our environment – much work remains to be done and that courageous individuals can make a difference.

Before there can be any legislation to protect honey bees, there must be evidence that bee kills occur with enough regularity to enact legislation in the first place. That is why beekeepers should report all bee kills at state and federal levels.

In the state of Georgia, report bee kills to Rachel Futch at the Georgia Department of Agriculture. Phone is 470-270-3044 or rachel.futch@agr.georgia.gov. (Any issues check https://www.agr.georgia.gov/pesticides.aspx for the Pesticide Complaints and Enforcement contact.)

National Pesticide Information Center for additional federal level reporting:

https://www.epa.gov/pollinator-protection/report-bee-kills


Additional Resources

Updated: 03 Feb 22

Neonicotinoids (also called Neonics) are now the most widely used insecticides in the world and the most studied class of insecticides for bees. They were developed in the 1990s in response to pest resistance and can target several pests in the Homoptera, Coleoptera, and Lepidoptera family. They are also less toxic to vertebrates than common older insecticides due to their increased selectivity to insect acetylcholine receptors in the brain. These benefits have led to their widespread use in agriculture and residential areas; however, they have been under scrutiny due to their persistence in the soil, ability to leach into the environment, high water solubility, and potential negative health implications for non-target organisms such as pollinators. The contradictory findings for the effects of neonicotinoids on honey bees has caused them to be a very controversial topic for policy decisions.
Pollinator Network @ Cornell

Links to information