Before discussing the compromise and its results on both the mosquitoes and honey bees, a little background information is in order.  On September 5, 1996, Hurricane Fran made landfall near Wilmington, NC and plowed through eastern North Carolina leaving a trail of economic damage that is unsurpassed in recent North Carolina history.  The storm actually moved inland all the way to Raleigh, the state capital, before it was downgraded from a hurricane to a tropical storm, a distance of approximately 120 miles.  The economic damage to the state exceeded a billion dollars.
  In addition to property damage, beach erosion, power outages, and human suffering, there was an added impact of the storm.  The numbers of mosquitoes increased dramatically in many of the state's southeastern counties due to Hurricane Fran.  The hurricane dropped tremendous amounts of water and also relocated standing water throughout its path.  This increase and relocation of standing water created excellent conditions for mosquitoes.  Mosquito populations are normally high in late summer and early fall, and Hurricane Fran produced numbers that were almost unbelievable in North Carolina.  Mosquito landings reached 60 per minute and often as high as 100 per minute after the hurricane.  Mosquito landings mean the number of mosquitoes that land on a person in a 60 second (one minute) time span.  In addition, there was also one documented death due to mosquito carried encephalitis in the state.  What to do?
The large numbers of mosquitoes plus the danger of encephalitis (a mosquito carried disease) immediately created the need to do something about the problem.  One simple solution to the problem would be to initiate a massive pesticide spray program using aircraft to apply mosquito-toxic pesticides to all of the area that was experiencing mosquito problems.  In addition, the pesticide should be applied during the daylight hours when aerial (aircraft) flight was best and when most of the mosquitoes were flying and susceptible to pesticide sprays.  The downside to this approach was that most of the mosquito-toxic pesticides are also toxic to honey bees, and honey bees would be most at risk during daylight hours.  Combine this with the fact that southeastern North Carolina had already lost over 1/3 of the managed beehives and 90% of the feral (wild) bee colonies in the past several years, and there was the real risk that honey bees might be practically eliminated from areas of North Carolina.
The responsible agency regarding the mosquito problem was the Public Health Pest Management Section of the NC Department of Environment, Health and Natural Resources.  Dr. Nolan Newton from that agency solicited information from the agencies and organizations that might be involved with any mosquito spray program.  Turnaround time was short because of the urgency of the matter and spraying actually began on September 19th in some counties (two weeks after the hurricane).  The potential impact on honey bees and beekeeping was a major consideration from the start and advice was requested from the apicultural programs at NC State University and the NC Department of Agriculture as well as the NC State Beekeepers Association.  Everyone agreed that there was a need to spray for mosquito control, but it must be done in a way that would minimize bee kills.

A compromise solution was developed with the following guidelines:
1.  Pesticides would be applied using both aerial and ground equipment, but a considerable amount of the spraying would be done by air because of its efficiency in this situation.
2.  The pesticides to be used in the aerial application would be limited to two products: Malathion and Resmethrin. Both of these products are toxic to bees but they would be applied as ultra-low volume sprays.  For example, the Malathion was applied at levels of three (3) ounces per acre.  In addition, the products would be applied to minimize bee contact (see #'s 3 & 4).
3.  Only populated areas of the state would be sprayed with pesticides for mosquito control.  This meant that bees in rural areas (i.e., bees used for pollination) and bees in undeveloped areas (both managed and feral bee colonies) would not be exposed to pesticide sprays.  This restriction on pesticide spraying did ensure that the populated areas where mosquitoes were the most serious problem would be treated; however, bees in those areas belonging to hobby beekeepers would be at some risk.
4. To minimize the risks to bee colonies and beekeepers in populated areas the following restrictions were also applied:
a. The citizens (including beekeepers) in the areas to be sprayed were notified at least 24 hours in advance by announcements defining the spray areas through the media (newspapers, radio, TV, etc.)

b. North Carolina State University and the NC Department of Agriculture pooled their lists of beekeepers to provide notice and advice to beekeepers in the areas to be sprayed.  This was done in cooperation with the local Cooperative Extension Service county offices.  The advice consisted of recommendations on how to minimize bee kills in a spray area.  In addition, officials from the NC Public Health Pest Management Section informed all county and local governments of the responsibility to notify beekeepers on the state lists and to provide the aerial applicators with any information on apiary locations.

c. The aerial application of pesticides was limited to the following times:

- No applications before 3:00 p.m. to minimize contact with foraging bees (with the following exception)

- Applications would be permitted prior to 10:00 a.m. if the temperature was below 650F.  If early morning spraying was conducted, then it had to be ended at 10:00 a.m. regardless of weather conditions.
 

Of all the compromises that were enacted, the time of day for spraying might be the one to be questioned by some beekeepers.  It was not realistic to spray at night because of the limitations on the aircraft involved in the aerial applications.  In addition, some of the mosquito populations could not be controlled by night spray programs.  The 3:00 p.m. start for allowing aerial spraying was based on records of bee foraging activity that had been collected in various NCSU bee studies.  There was some concern that the cooler temperatures in October combined with the fall nectar flows from goldenrod and aster might prolong bee flight into the late afternoon and even early evening.  Because of the weather conditions during the spray program, this was not a significant problem.
 
 
 

Compromise is a great idea, but did this plan really work?  Were the mosquitoes controlled and bee losses kept to a minimum?  The answer is Yes to both questions.  Approximately $4 million dollars was spent on the spray program and the mosquitoes were brought under control.  From the beekeepers' standpoint, only one documented claim was submitted for a bee loss due to the pesticide spray program.  It should be noted that beekeepers were encouraged to report any and all bee losses.

 Fig. 2 - DC-3 in flight and spraying Malathion for mosquito control in Columbus County (southeastern North Carolina).
 

The one bee loss that was reported consisted of two hives of bees that did suffer bee kills when a helicopter flew over the hives and sprayed pesticide.  Unfortunately, the county agency responsible for that spray program failed to notify the beekeeper in advance, but the agency did assume responsibility and reimbursed the beekeeper for his losses.  It is regrettable that any bees were killed, but it is a real testimonial to the cooperation between the interests involved that the mosquito problem was eliminated and bee kills were very, very low.
In recent years, the general public as well as many agencies without any honey bee responsibility have realized that the honey bee population in this country has been significantly reduced.  They are also becoming aware of the importance of bees and the consequences of additional bee losses.  This climate of understanding can be a real asset to beekeepers in situations such as the mosquito problem in southeastern North Carolina.

Photo Credit: Both photographs were
made by Dr. Alice Anderson , N.C.
Dept. of Environment, Health and
Natural Resources.
 
 
 

* Reprinted from Volume 137, No.2, February, 1997 American Bee Journal