Why Spraying for Disease-Carrying Mosquitoes is Bad for Our Bees

In the feud between mosquito-borne viruses and humans, honeybees’ lives hang in the balance.

By George EconomosNovember 4, 2016 10:53 am|

As Texas slowly cools down for the winter, mosquitoes should start dying off. But the risk of the spread of  mosquito-borne diseases remains even when temperatures hover as low as 50 degrees.

The central Texas city of Georgetown recently caught a mosquito carrying the West Nile Virus. So Texas health officials are not yet breathing easy about the potential spread of other diseases – including Zika, the virus linked to birth defects.

Whitney Qualls is a Medical Entomologist with the Texas Department of State Health Services.

“So we’re absolutely concerned,” Qualls says. “Our main goal is to ensure that we’re protecting public health. And that we’re promoting personal protection like wearing repellents, ensuring that people are dumping standing water in and around their home – because that’s where the mosquito that transmits Zika virus lives.”

In other parts of Texas another option is to spray insecticides. The city of Georgetown has used a vehicle to spray neighborhoods near where they found the mosquito carrying West Nile.

In August, public health officials in Dallas County authorized aerial spraying. But those insecticides don’t just kill mosquitoes, they have had some dire consequences on another insect: the honeybee. Public officials have a tight balancing act between insecticide use to protect against the spread of disease and the impact spraying has on pollinators.

As Dorchester County in South Carolina learned earlier this year, spraying can also kill bees – millions of them.

Walter Schumacher leads the Austin non-profit the American Honey Bee Protection Agency.

“In Texas if they were going to spray for mosquitoes and one-third of the cows in the morning were all dead, people would pay hell,” he says. ”And that’s because somebody would have killed their livestock. They wouldn’t have just said ‘Oh poor insect,’ they would have gone ‘We did something wrong.’”

Juliana Rangel from the Texas A&M Honey Bee Lab says the concern for bees should be high not just because they provide backyard beekeepers honey, but because they play an integral role in the food chain.

“The diversity of the food we consume and the quality of the food would definitely suffer,” she says. “In particular, a lot of our favorite fruits, vegetables, nuts, would either go away completely or their quality would be completely compromised – and/or their availability would be limited and their prices would skyrocket.”

So while Texas prepares to fight the Zika virus, it’s clear officials shouldn’t ignore bees. State Entomologist Qualls says there’s a plan in place to prevent the honeybee kill-off that happened in South Carolina from happening here.

“Here in Texas we and many of our mosquito control programs have a list of people that they would go and contact,” Qualls says. “If you’re applying [insecticides] even by ground or air, the control program will contact them – they’ll know to bring their hives in or put a cover on their hives to avoid any negative impact on their honeybee populations.”

But the same notification program was in place in South Carolina. What happened? Joe Conlon with the American Mosquito Control Association says they made a mistake.

Wiping out the honeybee population could be a pretty scary slip-up when it comes to the food supply. But Conlon says with dangerous diseases such as West Nile and Zika fighting to establish a foothold in Texas, it’s not so easy to define where to draw the line.

“The balance should always tip in favor of human health,” Conlon says. “Are there risks in utilizing pesticides? Indeed there are, and we’re very much aware of those risks – as there are risks in utilizing aspirin, and things of that nature, all medicines. And these are kinds of environmental medicines in their own part. These pesticides are an unnatural thing that we’re doing because mosquitoes are a natural part of our environment and to get rid of them we have to do something completely unnatural to effectuate that.”

As winter approaches and mosquitoes die off, public health officials may have more time to weigh the benefits and risks of aerial spraying. Either way, experts say the consequences could be severe.