Since the accidental introduction of more than two dozen African honey bee queens into Sao Paulo, Brazil in 19571, these insects have spread throughout South and Central America and up into the southern United States, usurping and replacing the less well adapted European honey bees (EHB) in the feral population. These hybrid Africanized honey bees (AHB) have traits that put them in conflict with both humans and wildlife. They exhibit highly defensive behavior, reproduce very fast, and are less selective about where they make a home1,2.

Although nest boxes have long been used by ornithologists to enhance breeding by cavity-nesting birds3,4, their use has been shown to be especially effective for enhancing the breeding of threatened and endangered parrots in the tropics5,6. Unfortunately, Africanized honey bees often choose these same nest boxes – sometimes even killing the occupants. Additionally, these AHB pose a significant threat to biologists when they are conducting nest studies. In areas of South America where AHB have been established, several parrot conservation projects have seen their artificial nest boxes occupied by AHB7-10. Competition for nest boxes with honey bees is widespread and is not confined to parrots. Many other bird species both in the New and Old World are affected11-15. Without efforts to mitigate the threat of these invasive AHB, recent successes in parrot conservation could be lost.

Current practices for managing competition from bees includes the use of repeated, high doses of permethrin7, manually removing swarms, closing nest entrances immediately after breeding season8, or the application of chemicals to the outsides of nest boxes15. The labor involved and the danger to biologists render these strategies less than optimal. Development of a prevention protocol is warranted.

Honey bee colonies multiply via a process known as swarming, when the old queen leaves the colony with up to three fourths of the worker bees16. Africanized honey bees' high reproductive rate allows them to swarm more frequently (four to eight times per year) than EHB (who swarm once or twice per year)17. Moreover, AHB may swarm throughout the year rather than during a particular season like EHB. Consequently, AHB can quickly occupy most of the suitable nesting sites in a given area.

Honey bee house hunting behavior can be utilized to influence their choice of nest site. A small fraction of bees in a swarm fly off to locate and inspect new potential nest sites. Several potential nest sites are scouted for simultaneously. These scout bees return to the swarm and perform dances to indicate the location of the site. The stronger the dancing is for a site, the faster the number of scout bees builds up at that site18. Therefore, bees dance stronger for better quality sites, compared to sites that are mediocre or poor. Once a quorum threshold is reached, the swarm takes off and flies to the new chosen home site18.

Sub-lethal contact doses of the insecticide permethrin hamper a scout bee's ability to orient and reduce its activity level19,20. An application of permethrin inside nest boxes at first should be repellant to scout bees21, and overtime as the chemical degrades, scout bees exposed to permethrin during their assessment of the box, should be rendered less able to perform strong recruitment dances, decreasing the amount of scout bees recruited to the site. A more suitable (ideal cavity volume, small entrance hole located at the bottom, and a pheromone attractant) alternate nest site is provided in the form of a trap box for the bees. This excellent trap site should reach a quorum faster than the insecticide treated bird box leading the swarm to choose the trap box over the bird box.

As an example, we describe an experiment to reduce colonization of Barn Owl artificial nest boxes by AHB in South Florida sugarcane fields. Our objective was to test the effectiveness of using a push-pull method that will "push" bees away from owl nest boxes treated with an insecticide and "pull" them toward pheromone baited swarm traps.